Collecting external accessory data at a mobile data collection platform that obtains raw observables from an external gnss raw observable provider

ABSTRACT

External accessory data is collected at a mobile data collection platform provided by an external accessory of the mobile data collection platform. An image that includes a point of interest is captured by an image capturing device that is an integral part of the mobile data collection platform performs. Raw observables are obtained from an external GNSS raw observable provider that is separate from and outside of the mobile data collection platform. A position fix of the mobile data collection platform is determined based on the raw observable. Orientation information comprising a tilt angle and an azimuth angle is determined. External accessory data is received from an accessory that is external to the mobile data collection platform. The image, the position fix, the orientation information and the external accessory data are stored in hardware memory of the mobile data collection platform.

CROSS-REFERENCE TO RELATED APPLICATIONS (CONTINUATION-IN-PART)

This application claims priority to and is a continuation-in-partapplication of co-pending U.S. patent application Ser. No. 14/035,884,filed on Sep. 24, 2013 entitled, “EXTRACTING PSEUDORANGE INFORMATIONUSING A CELLULAR DEVICE,” by Rudow et al., having Attorney Docket No.TRMB-3172.CIP1.

U.S. patent application Ser. No. 14/035,884 claimed priority to andbenefit of then co-pending U.S. Provisional Patent Application No.61/746,916, filed on Dec. 28, 2012 entitled, “IMPROVED GPS/GNSS ACCURACYFOR A CELL PHONE,” by Rudow et al., having Attorney Docket No.TRMB-3172.PRO, and assigned to the assignee of the present application;the contents of U.S. Provisional Patent Application No. 61/746,916 wereincorporated by reference into U.S. patent application Ser. No.14/035,884.

Application Ser. No. 14/035,884, also claimed priority to and is acontinuation-in-part to the co-pending patent application Ser. No.13/842,447, Attorney Docket Number TRMB-3172, entitled “OBTAININGPSEUDORANGE INFORMATION USING A CELLULAR DEVICE,” by Richard Rudow, withfiling date Mar. 15, 2013, and assigned to the assignee of the presentapplication, the disclosure of which was incorporated by reference intoapplication Ser. No. 14/035,884.

This application claims priority to and is a continuation-in-partapplication of co-pending U.S. patent application Ser. No. 14/515,317,filed on Oct. 15, 2014 entitled, “PERFORMING DATA COLLECTION BASED ONINTERNAL RAW OBSERVABLES USING A MOBILE DATA COLLECTION PLATFORM,” byRudow et al., having Attorney Docket No. TRMB-3172.CIP7.

BACKGROUND

The Global Positioning System (GPS) and its extensions in the GlobalNavigation Satellite Systems (GNSS) have become thoroughly pervasive inall parts of human society, worldwide. GPS and GNSS receivers in theform of chipsets have become widely incorporated into cell phones andother types of cellular devices with cellular-based communicationsequipment.

Typically, cellular devices include highly integrated GNSS chipsets thatare designed to work with the E-911 service primarily, and are notdesigned to provide anywhere near a full range of features and outputs.They do provide a position fix, but are not designed to make availablevery many other parameters of interest. All GNSS receivers must acquire,track and decode a data message that conveys information about thelocation of the satellites in space, and time information. The principaladditional parameter obtained is the “pseudorange.” However,conventionally, this set of data is not available as an output from thecellular device's GNSS chipsets for use by the cellular device itself.Conventionally, in circumstances where it is available, it is underaccess control by the vendor.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawings, which are incorporated in and form a part ofthis application, illustrate embodiments of the subject matter, andtogether with the description of embodiments, serve to explain theprinciples of the embodiments of the subject matter. Unless noted, thedrawings referred to in this brief description of drawings should beunderstood as not being drawn to scale. Herein, like items are labeledwith like item numbers.

FIG. 1A depicts a block diagram of a cellular device for extractingpseudorange information, according to one embodiment.

FIG. 1B depicts a block diagram of a cellular device for extracting andprocessing pseudorange information, according to one embodiment.

FIG. 1C depicts decision logic for determining whether to apply WAAS(Wide Area Augmentation System) corrections or DGPS (Differential GlobalPositioning System) corrections, according to one embodiment.

FIG. 1D depicts a block diagram of a cellular device for extractingpseudorange information, according to one embodiment.

FIG. 2 depicts a block diagram of multiple sources for providingpositioning correction information to a cellular device for processingpseudorange information, according to one embodiment.

FIG. 3 depicts a conceptual view of pseudorange measurements, accordingto various embodiments.

FIG. 4 depicts a flowchart for determining an RTK (Real Time Kinematic)position solution, according to one embodiment.

FIG. 5A is a flowchart of a method for performing a carrier phasesmoothing operation using real carrier phase information, according toone embodiment.

FIG. 5B is a flowchart of a method for generating reconstructed carrierphase information based on Doppler shift, according to one embodiment.

FIG. 6 depicts a flowchart of a method of extracting pseudorangeinformation using a cellular device, according to one embodiment.

FIGS. 7A-10 depict flowcharts of methods of improving the positionaccuracy using one or more position accuracy improvements, according tovarious embodiments.

FIG. 11 depicts a flowchart a method of accessing and processingextracted pseudorange information, according to one embodiment.

FIG. 12 depicts a block diagram of a GNSS receiver, according to oneembodiment.

FIG. 13 depicts an example Kalman filtering process, according to someembodiments.

FIG. 14 depicts a block diagram of a mobile data collection platform,according to one embodiment.

FIG. 15 depicts another block diagram of a mobile data collectionplatform, according to one embodiment.

FIG. 16 depicts a block diagram of processing logic for mobile datacollection platform, according to one embodiment.

FIG. 17 depicts processing logic for mobile data collection platform,according to one embodiment.

FIG. 18 depicts processing logic, according to one embodiment.

FIG. 19 depicts an image plane relative to an image capture device,according to one embodiment.

FIG. 20 depicts a pattern that can be used for calibrating a mobile datacollection platform, according to one embodiment.

FIG. 21 depicts a calibration image that is an image that the imagecapturing device took of the pattern depicted in FIG. 20, according toone embodiment.

FIG. 22 depicts a three dimensional view of relationships between thelocal coordinate system (also known as the “earth coordinate system”),the platform coordinate system of a mobile data capturing device, and apointing vector of an image capturing device, according to oneembodiment.

FIG. 23 depicts a three dimensional view of a mobile data collectionplatform (MDCP) that is being used to perform data collection, accordingto one embodiment.

FIG. 24 depicts a side view of a mobile data collection platform,according to one embodiment.

FIG. 25 depicts a top view of a mobile data collection platform (MDCP),according to one embodiment.

FIG. 26 depicts a three dimensional top view of a mobile data collectionplatform, according to one embodiment.

FIG. 27 depicts a graphical user interface that can be displayed on themobile data collection platform's display, according to one embodiment.

FIG. 28 depicts a top down view of a field of view, according to oneembodiment.

FIG. 29 depicts a three dimensional view of a mobile data collectionplatform that is being used to perform data collection, according to oneembodiment.

FIG. 30 depicts the same scene depicted in FIG. 29 from a top view,according to one embodiment.

FIG. 31 depicts a side view of the same scene depicted in FIGS. 30 and29 from a side view, according to one embodiment.

FIG. 32 depicts a top view of a scene where a mobile data collectionplatform is used to take two images of a point of interest, according toone embodiment.

FIG. 33 is a flowchart of a method for generating a bubble level overlayon a display in accordance with one embodiment.

FIG. 34 is a flowchart of a method for implementing an aiming aidoperation in accordance with one embodiment.

FIG. 35 depicts a flowchart of a method of performing data collectionusing a mobile data collection platform, according to one embodiment.

FIG. 36 depicts a flowchart of a method of performing data collectionusing a mobile data collection platform, according to one embodiment.

FIG. 37 depicts a block diagram of a mobile data collection platformsystem, according to one embodiment.

FIG. 38 depicts an external GNSS raw observable provider in a knownspatial relationship with a mobile data collection platform, accordingto one embodiment.

FIG. 39 depicts an outside view of an external GNSS raw observableprovider, according to one embodiment.

FIG. 40 depicts a block diagram of a mobile data collection platform,according to one embodiment.

FIG. 41 depicts software and hardware memory of a mobile data collectionplatform, according to various embodiments.

FIG. 42 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform with an entrance pupil and flashoriented in a side position, according to one embodiment.

FIG. 43 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform with an entrance pupil and flashoriented in a center position, according to one embodiment.

FIG. 44 depicts a block diagram of an external accessory, according toone embodiment.

FIG. 45A depicts a block diagram of features of an external electronicdistance measurement accessory, according to one embodiment.

FIG. 45B depicts, a compact external electronic distance measurementaccessory, according to one embodiment.

FIG. 45C depicts a block diagram of a legacy electronic distancemeasurement (also known as an off-the-shelf EDM or conventional EDM),according to one embodiment.

FIGS. 45D and 45E display respective legacy EDMs that are mountedperpendicularly with an MDCP so that the legacy EDM's principal axis andthe MDCP's principal axis are perpendicular to each other, according tovarious embodiments.

FIGS. 45F-45H depict an MDCP coupled with an EDM includes a mirror tobend received light and with respective principal axis that areparallel, according to one embodiment.

FIGS. 46A-46C depict views of the outsides of various externalaccessories, according to various embodiments.

FIGS. 47-56 depict various types of coupling mechanisms for coupling amobile data collection platform with one or more external accessories,according to various embodiments.

FIG. 57 depicts a case with a fastener option, according to one or moreembodiments.

FIG. 58 depicts block diagrams of accessory activation logic andaccessory accessing logic, according to various embodiments.

FIG. 59 depicts processing logic of an external accessory, according toone embodiment.

FIG. 60 depicts a flowchart of a method for collecting externalaccessory data at a mobile data collection platform provided by anexternal accessory of the mobile data collection platform, according toone embodiment.

FIG. 61 depicts a flowchart of a method for collecting externalaccessory data at a mobile data collection platform provided by anexternal accessory of the mobile data collection platform, according toanother embodiment.

FIG. 62 depicts a flowchart of a method for collecting externalaccessory data at a mobile data collection platform provided by anexternal accessory of the mobile data collection platform, according toyet another embodiment.

FIG. 63 depicts a flowchart of a method for determining a distance,according to one embodiment.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to various embodiments of thesubject matter, examples of which are illustrated in the accompanyingdrawings. While various embodiments are discussed herein, it will beunderstood that they are not intended to limit to these embodiments. Onthe contrary, the presented embodiments are intended to coveralternatives, modifications and equivalents, which may be includedwithin the spirit and scope the various embodiments as defined by theappended claims. Furthermore, in the following Description ofEmbodiments, numerous specific details are set forth in order to providea thorough understanding of embodiments of the present subject matter.However, embodiments may be practiced without these specific details. Inother instances, well known methods, procedures, components, andcircuits have not been described in detail as not to unnecessarilyobscure aspects of the described embodiments.

Unless specifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the description ofembodiments, discussions utilizing terms such as “accessing,”“calculating,” “extracting,” “using,” “providing,” “applying,”“correcting,” “smoothing,” “reconstructing,” “modeling,” “improving,”“adjusting,” “filtering,” “discarding,” “removing,” “processing,”“determining,” “selecting,” “locating,” “positioning,” “increasing,”“differentiating,” “integrating,” “bridging,” displaying,” “performing,”“obtaining,” “receiving,” “storing,” “notifying,” “matching,”“creating,” “generating,” “communicating,” “transmitting,” “requesting,”“activating, “deactivating,” “initiating,” “terminating,”“interpolating,” “changing,” “replacing,” “causing,” “transformingdata,” “modifying data to transform the state of a computer system,” orthe like, refer to the actions and processes of a computer system, datastorage system, storage system controller, microcontroller, hardwareprocessor, or similar electronic computing device or combination of suchelectronic computing devices. The computer system or similar electroniccomputing device manipulates and transforms data represented as physical(electronic) quantities within the computer system's/device's registersand memories into other data similarly represented as physicalquantities within the computer system's/device's memories or registersor other such information storage, transmission, or display devices.

I. Extracting Pseudorange Information Using a Cellular Device Overview

Cellular devices, such as cell phones and non-voice enabled cellulardevices, possesses pseudorange information that can be used in surveyingand other positioning operations. Conventionally, however, thepseudorange information from cellular device chipsets are only availableunder a limited set of conditions, usually only when performing a E-911service call, and then only for use by the Assisted GPS service locatedin conjunction with the E-911 service facility. Therefore, according toone embodiment, an embedded GNSS chipset is employed with in a cellulardevice, which: a) calculates pseudorange information for use by the GNSSchipset; and b) permits extraction of this pseudorange information bythe cellular device in which it is embedded. As will be discussed, thepseudorange information from the GNSS chipset is extracted for useelsewhere in the cellular device outside of the GNSS chipset.

Examples of Systems for Extracting Pseudorange Information

FIG. 1A depicts a block diagram of a cellular device 100 for extractingpseudorange information, according to one embodiment. Examples of acellular device 100 include a cell phone, a non-voice enabled cellulardevice, and a mobile hand-held GNSS receiver. The cellular device may bemobile or stationary. The cellular device may be hand-holdable orincorporated as a portion of a system which is not hand-holdable. Insome embodiments, a cellular device, such as cellular device 100, may beutilized as a portion of a navigation system, security system, safetysystem, telematics device/box, or the like. In some embodiments,cellular device 100 may be utilized as sub-system of the vehicle mountedportion of a vehicle safety system, security system, and/or navigationsystem. The vehicle mounted portion of the OnStar® vehicle safety,vehicle security, and vehicle navigation system that is utilized in manyvehicles is one non-limiting example of a system which may includecellular device 100.

As depicted in FIG. 1A, the cellular device 100 includes a GNSS chipset170, a GNSS receiver 107, a processor 172 that is part of the GNSSreceiver 107, a chipset accessor logic 141, a pseudorange informationextractor logic 142, an improved accuracy Secure User Platform Location(SUPL) client 101, a pseudorange information bridger logic 143, apseudorange information processing logic 150, an operating system 160, alocation manager logic 161, a location displayer logic 162, hardware 180that is outside of the GNSS receiver 107. According to one embodiment,the chipset accessor logic 141, the pseudorange information extractorlogic 142, the pseudorange information processing logic 150, and thepseudorange information bridger logic 143 are a part of the improvedaccuracy SUPL client 101.

According to one embodiment, the hardware 180 includes a hardwareprocessor 109 and memory 210. An example of a hardware processor 109 isa central processing unit. An example of hardware memory 210 is computerreadable storage, such as, but not limited to, a disk, a compact disk(CD), a digital versatile device (DVD), random access memory (RAM) orread only memory (ROM). The hardware memory 210 is physical and,therefore, tangible, according to one embodiment. The hardware memory210, according to another embodiment, is non-transitory.

According to one embodiment, the processor 172 and the GNSS receiver 107are a part of the GNSS chipset 170. According to one embodiment, thechipset accessor logic 141, pseudorange information extractor logic 142,the pseudorange information bridger logic 143, the improved accuracySUPL client 101, the operating system 160, and the processor 109 arelocated in a portion of the cellular device 100 that is outside of theGNSS chipset 170. The location manager logic 161 can be a part of theoperating system 160 and external to the GNSS chipset 170. According toone embodiment, the location displayer logic 162 is a part of thelocation manager logic 161. According to one embodiment, the chipsetaccessor logic 141, pseudorange information extractor logic 142, thepseudorange information processing logic 150, pseudorange informationbridger logic 143, and improved accuracy SUPL client 101 are applicationprogramming interfaces (API) function applications that reside in memoryof the cellular device 100 and are executed by a processor 109 of thecellular device 100.

According to one embodiment, the GNSS receiver 107 is capable ofreceiving signals from GPS satellites, GLONASS satellites, or from acombination of satellites from different constellations. The GNSSreceiver 107 can perform GPS measurements to derive raw measurement datafor a position of the cellular device 100. The raw measurement data canprovide an instant location of the cellular device 100. According to oneembodiment, the raw measurement data is the pseudorange information thatis extracted (also referred to as “extracted pseudorange information”).Examples of the extracted pseudorange information are uncorrectedpseudorange information, observed pseudorange information, or unsmoothedpseudorange information, or a combination thereof. Conventionally, theraw measurement data is only for use by the GNSS chipset 170 and theGNSS chipset 170 calculates pseudorange information that is only for useby the GNSS chipset 170. Examples of pseudorange information areuncorrected pseudorange information, smoothed pseudoranges, andcorrected pseudoranges. Examples of corrections used to improve accuracyof a position fix include differential GNSS corrections (DGPS), highprecision GNSS satellite orbital data, GNSS satellite broadcastephemeris data, and ionospheric and tropospheric error corrections anderror projections based on location.

The GNSS chipset 170 has a processor 172 and, therefore, is capable ofprocessing information, such as pseudorange information, itself.However, according to various embodiments, information that the GNSSchipset 170 has can be extracted from the GNSS chipset 170 and processedoutside of the GNSS chipset 170 instead of by the GNSS chipset 170 usingits own processor 172, in order to provide an improved accuracy positionfix.

The chipset accessor logic 141 is configured for accessing the GNSSchipset 170. The pseudorange information extractor logic 142 isconfigured for extracting the pseudorange information from the accessedGNSS chipset 170. The extracted pseudorange information can be receivedand stored continuously. The pseudorange information bridger logic 143is configured for bridging the pseudorange information from the GNSSchipset 170 to the location manager logic 161 that resides in theoperating system 160 of the cellular device 100.

According to one embodiment, the chipset accessor logic 141, thepseudorange information extractor logic 142, the pseudorange informationprocessing logic 150 and pseudorange information bridger logic 143 are apart of an improved accuracy SUPL client 101. For example, The SUPLclient 101 can interface between the GNSS chipset 170 and the locationmanager logic 161, which resides in the operating system 160.

The pseudorange information can be obtained from the processor 172 ofthe GNSS receiver 107. The GNSS chipset 170 may be designed, forexample, by the manufacturer of the GNSS chipset 170, to providerequested information, such as pseudorange information, in response toreceiving the command. The pseudorange information may be extracted fromthe GNSS chipset 170 using the command that the manufacturer hasdesigned the GNSS chipset 170 with. For example, according to oneembodiment, the GNSS chipset 170 is accessed using an operation that isa session started with a message that is an improved accuracy SecureUser Platform Location (SUPL) start message or a high precision SUPLINIT message. According to one embodiment, the message is a customcommand that is specific to the GNSS chipset 170 (also referred to as “aGNSS chipset custom command”) and by which the improved accuracy SUPLclient 101 can gain access to the raw measurements of the GNSS chipset170. Access may be controlled by the chipset manufacturer and a suitablekey made available for use in the SUPL for obtaining access to thepseudoranges. A suitable key is an example of a “custom command.”

A worker thread associated with the SUPL client 101 can monitor the rawmeasurements delivered by the GNSS chipset 170 into the GNSS chipset170's memory buffers, cache the raw measurements and use the rawmeasurements to determine a position fix. The pseudorange informationextractor logic 142 and the pseudorange information processing logic 150can be associated with the worker thread. For example, the pseudorangeinformation extractor logic 142 can cache the raw measurements and thepseudorange information processing logic 150 can determine the location.

According to one embodiment, a worker thread is a light weight processthat executes a specific sequence of tasks in the background. The taskscan be of long term and/or at times periodic in nature. The workerthread can assist in helping the main thread, which may also be referredto as the main program or main task, with specific functions. Workerthreads can be started when these functions of the sequence of tasks areto be executed. A worker thread can remain in the active state as longas its respective functions are being executed. A worker thread mayterminate itself, when it completes its functions or when it reaches apoint where it can no longer continue to function, for example, due toan irrecoverable error. A worker thread can post its status to the mainthread when it ends. Examples of posted status are completion ortermination. A worker thread may also post to the main thread the levelof progress of its functions periodically. At a given point in time,there may be many such worker threads in progress at the same time.Worker threads may maintain some sort of synchronization amongstthemselves depending upon the tasks they are intended for. The mainthread may terminate a worker thread, for example, when the functions ofthat worker thread are no longer needed or due to other executionchanges in the system.

According to one embodiment, the cellular device 100 can improve theaccuracy of the extracted pseudorange information. For example, thepseudorange information processing logic 150 can improve the accuracy ofthe extracted pseudorange information, as will become more evident.

The output of the pseudorange information processing logic 150 can beused for determining the location of the cellular device 100. Forexample, a latitude, longitude and altitude can be determined based onthe output of the pseudorange information processing logic 150, whichcan be displayed by the location displayer logic 162.

According to one embodiment, the pseudorange information bridger logic143 communicates the output from the pseudorange information processinglogic 150 to the location manager logic 161 in the operating system 160.According to one embodiment, the output of the pseudorange informationprocessing logic 150 is a location that is defined in terms of latitude,longitude, and altitude. The methods are well-known in the GPS arts. Thepseudoranges are used to first determine a location the WGS-84coordinate system of the Global Positioning System, and then convertedinto latitude, longitude, and elevation.

The location displayer logic 162 can display the location with respectto a digital representation of a map available, for example, from thirdparties via download to the cellular device.

FIG. 1B depicts a block diagram of a portion of a cellular device 100,100D for extracting pseudorange information, according to oneembodiment. The cellular device 100, 100D includes accessing-logic 110Band processing logic 150. The accessing logic 110B includes extractinglogic112B and receiving logic 114B. The extracting logic 112B includespseudorange information extracting logic 142, satellite-basedaugmentation system (SBAS), extracting logic 112B-5, WAAS extractinglogic 112B-2, Doppler shift extracting logic 112B-3, and carrier phasemeasurement extracting logic 112B-4. According to one embodiment, WAASis an example of SBAS. According to one embodiment, SBAS extractinglogic 112B-5 includes WAAS extracting logic 112B-2.

Examples of satellite-based augmentation system (SBAS) are Indian GPSaided Geo Augmented Navigation System (GAGAN), European GeostationaryNavigation Overlay Service (EGNOS), Japanese Multi-functional SatelliteAugmentation System (MSAS), John Deere's StarFire, WAAS, and Trimble'sOmniStar.

As depicted in FIG. 1B, the pseudorange information processing logic 150includes pseudorange-correction-logic 151,pseudorange-carrier-phase-smoothing-logic 152, position accuracyimprovement determination logic 180B and determining position fix logic170B. Examples of “improving” are “smoothing” or “correcting,” or acombination thereof. The pseudorange-correction-logic 151 includes WAASlogic 151A, DGPS logic 151B, Precise Point Positioning (PPP) logic 151C,RTK logic 151D, VRS (Virtual Reference Station) logic 151E, and RTXlogic 151F. The pseudorange-carrier-phase-smoothing-logic 152 includesreal carrier phase logic 152A and reconstructed carrier phase logic152B. According to one embodiment, the accessing-logic 110B and theprocessing logic 150 reside in the improved accuracy SUPL client 101.

Examples of pseudorange information are extracted pseudoranges,corrected pseudoranges, smoothed pseudoranges, or a combination thereof,among other things. Examples of pseudorange corrections include WideArea Augmentation System (WAAS) corrections, Differential GlobalPositioning System (DGPS) corrections, Precise Point Positioning (PPP)corrections, Real Time Kinematic (RTK) corrections, and VirtualReference Station (VRS) corrections. Examples of carrier phaseinformation include real carrier phase and reconstructed carrier phaseinformation.

The extracting logic 112B can extract various types of information fromthe GNSS chipset 170, as discussed herein. For example, the extractinglogic 112B includes pseudorange information extracting logic 142, WAASextracting logic 112B-2, Doppler extracting logic 112B-3, and carrierphase measurement extracting logic 112B-4. According to one embodiment,the extracting logic 112B can be used to extract these various types ofinformation from the GNSS chipset 170 in a similar manner that thepseudorange information extractor logic 142 extracts pseudorangeinformation from the GNSS chipset 170, for example, using an SUPL Client101 that employs a command designed or provided by the manufacturer ofthe GNSS chipset 170, as described herein. More specifically, the WAASextracting logic 112B-2, the Doppler extracting logic 112B-3, andcarrier phase measurement extracting logic 112B-4 can employ commandsdesigned or provided by the manufacturer of the GNSS chipset 170 toextract respectively WAAS, Doppler information, and carrier phasemeasurements for real carrier phase information.

The receiving logic 114B receives other types of information that arenot extracted from the GNSS chipset 170. The receiving logic 114B canreceive the information in response to a request (also commonly known as“pulling”) or receive the information without the information beingrequested (also commonly known as “pushing”). “Obtaining” and“accessing” can be used interchangeably, according to variousembodiments.

Table 1 depicts the types of information that are extracted from theGNSS chipset or received without extraction, as discussed herein,according to various embodiments.

TABLE 1 Types of Information that are Extracted from the GNSS Chipset orReceived without Extraction Extracted Received Pseudorange InformationWAAS/SBAS Doppler Shift Information DGPS Carrier Phase Measurements forreal carrier RTK phase information WAAS/SBAS Not Applicable

The information depicted in the extracted column can be extracted fromthe GNSS chipset 170 using the SUPL client 101 in a manner similar toextracting pseudorange information, as discussed herein. WAAS may beextracted or received, for example, over the Internet. When this Dopplershift information is available but real carrier phase information isnot, the extracted Doppler shift information can be integrated byprocessor 109, for example, to reconstruct carrier phase information.Techniques for reconstructing carrier phase information from Dopplershift information are well known in the art. Any one or more of theinformation depicted in Table 1 can be processed by the cellular device100, for example, using the processor 109 that is outside of the GNSSchipset 170.

The pseudorange-carrier-phase-smoothing-logic 152 can smooth pseudorangeinformation by applying carrier phase information to the pseudorangeinformation.

The pseudorange-carrier-phase-smoothing-logic 152 receives rawpseudorange information from the accessing logic 110B. The carrier phaseinformation may be reconstructed carrier phase information or realcarrier phase information.

The pseudorange-correction-logic 151 can correct pseudorangeinformation. For example, the pseudorange-correction-logic 151 canreceive pseudorange information and apply pseudorange corrections to thepseudorange information. Examples of the pseudorange informationreceived by the pseudorange-correction-logic 151 include extractedpseudorange information, DGPS corrected pseudoranges, and smoothedpseudoranges that were smoothed, for example, using either real carrierphase information or reconstructed carrier phase information. Examplesof pseudorange corrections that can be applied to the receivedpseudorange information are WAAS corrections, DGPS corrections, PPPcorrections, RTK corrections and VRS corrections. The PPP logic 151Cperforms Precise Point Positioning (PPP) processing on pseudorangeinformation. According to one embodiment, RTX™ is proprietary form ofPPP developed by Trimble Navigation Limited. It should be appreciatedthat there are other forms of Precise Point Positioning which mayoperate using similar principles.

The pseudorange information processing logic 150 may also include adetermining position fix logic 170B that performs, for example, a leastsquares solution 171B can be performed after the extracted pseudorangeinformation is improved by the pseudorange-correction-logic 151 or thepseudorange-carrier-phase-smoothing-logic 152, or a combination thereofand prior to transmitting the output to the pseudorange informationbridger logic 143. According to one embodiment, the determining positionfix logic 170B resides in the processing logic 150. Least-squaressolution methods are well-known in the position determination arts.

According to one embodiment, extracted pseudorange information is passedfrom the extracting pseudorange information logic 142 to the smoothinglogic 152 where it is smoothed at either real carrier phase logic 152Aor reconstructed carrier phase logic 152B. According to one embodiment,the smoothed pseudorange information is communicated from the smoothinglogic 152 to the correcting logic 151 for further correction, where oneor more corrections may be performed. If a plurality of corrections isperformed, they can be performed in various combinations. If carrierphase smoothing is not possible, the extracted pseudorange informationcan be communicated from extracting pseudorange information logic 142 tocorrection logic 151. One or more of the logics 152A, 152B, 151A, 151E,151F in the processing logic 150 can communicate with any one or more ofthe logics 152A, 152B, 151A, 151E 151F in various orders andcombinations. Various embodiments are not limited to just thecombinations and orders that are described herein. According to oneembodiment, extracted pseudorange information may not be smoothed orcorrected. In this case, unsmoothed uncorrected pseudorange informationcan be communicated from logic 142 to logic 170B.

The cellular device 100 may also include aposition-accuracy-improvement-determination-logic 180B for determiningwhether to apply any improvements and if so, the one or more positionaccuracy improvements to apply to the extracted pseudorange information.For example, the cellular device 100 may be preconfigured based on thesignals that are available to the cellular device 100 or a user of thecellular device 100 may manually configure the cellular device 100. Forexample, the cellular device 100 can display the signals that areavailable to the user and the user can select which signals they desirefrom the displayed list of signals. The configuration information,whether preconfigured or manually configured by the user, can be storedfor example, in a look up table in the cellular device 100. Examples ofposition improvements that can be determined by the position accuracyimprovement determination logic 180B are real carrier phase information,reconstructed carrier phase information, WAAS, DGPS, PPP, RTX™, RTK andVRS. The position accuracy improvement determination logic 180B can beused to determine to reconstruct carrier phase information based onDoppler shift if real carrier phase information is not available, forexample. The position-accuracy-improvement-determination-logic 180B,according to one embodiment, is a part of the SUPL client 101.

Extracted pseudorange information without any additional improvementsprovides 4-5 meters of accuracy. Various combinations of positionaccuracy improvements can be applied to extracted pseudorangeinformation (EPI) according to various embodiments, where examples ofposition accuracy improvements include, but are not limited to, WideArea Augmentation System (WAAS) pseudorange corrections, DifferentialGPS (DGPS) pseudorange corrections, Precise Point Positioning (PPP)processing, RTX™, Real Time Kinematic (RTK), Virtual Reference Station(VRS) corrections, real carrier phase information (real CPI) smoothing,and reconstructed carrier phase information (reconstructed CPI)smoothing.

One or more of the logics 110B, 112B, 114B, 142, 112B-2, 112B-3, 180B,152, 152A, 152B, 151, 151Aj-151F, 170B, 171B can be executed, forexample, by the processor 109 of the cellular device 100 that is locatedoutside of the GNSS chipset 170.

Table 2 depicts combinations of information that result in a positionfix 172B, according to various embodiments. However, various embodimentsare not limited to the combinations depicted in Table 2.

TABLE 2 Combinations of Information that Result in a Position FixCombination Combinations of Information that Identifier Result in aPosition Fix 1 Extracted pseudorange information (EPI) 2 EPI + Real orReconstructed Carrier Phase Information (CPI) 3 EPI + CPI + WAAS 4 EPI +CPI + WAAS + DGPS 5 EPI + CPI + DGPS 6 EPI + CPI + DGPS + PPP 7 EPI +DGPS 8 EPI + DGPS + WAAS 9 EPI + DGPS + PPP 10 EPI + RTK 11 EPI + VRS

FIG. 1C depicts decision logic 151H for determining whether to applySBAS corrections 151G, WAAS corrections 151A, PPP corrections 151C, RTX™corrections 151F or DGPS corrections 151B, according to one embodiment.According to one embodiment, the SBAS corrections that are applied areWAAS corrections. According to one embodiment, the decision logic 151His located in the position accuracy improvement determination logic 180Bor the correction logic 151.

According to one embodiment, a first position is determined by anavailable means. For example, the first position may be based onuncorrected unsmoothed extracted pseudorange information, cellular towertriangulation, WiFi triangulation or other means. A level of precisionmay be selected, for example, by a user or preconfigured into thecellular device, where DGPS or one or more of SBAS, WAAS, RTX™, PPPwould be used to achieve that level of precision. The decision logic151H can access the level of precision and receive two or more referencestation locations by sending a message to a database inquiring aboutnearby reference stations for DGPS. The decision logic 151H candetermine the distance between the cellular device 100 and the nearestreference station. If the distance is greater than some selecteddistance threshold, the decision logic 151H can use PPP, RTX™, SBAS orWAAS, instead of DGPS. If the distance is less than the selecteddistance threshold, the decision logic 151H can use DGPS instead of PPP,RTX™, SBAS or WAAS. According to one embodiment, a range for a distancethreshold is approximately 20 to 60 miles. According to one embodiment,the distance threshold is approximately 60 miles.

If the decision logic 151H determines to apply DGPS corrections at DGPSlogic 151B resulting in DGPS corrected smoothed pseudoranges, furthercorrections can be made using the orbit-clock information contained inthe PPP corrections. For example, a position fix can be determined basedon the DGPS corrected smoothed pseudoranges and the PPP corrections. Theposition fix can be determined external to the GNSS chipset, forexample, at the processing logic 150.

The cellular device 100 may be configured with the distance threshold,for example, by the manufacturer of the cellular device 100 or by a userof the cellular device 100. The cellular device 100 may be configuredwith the distance threshold through service that is remote with respectto the cellular device 100 or may be configured locally. The distancethreshold can be selected based on a degree of position accuracy that isdesired.

FIG. 1D depicts a block diagram of a cellular device 100D for extractingpseudorange information, according to one embodiment.

As depicted in FIG. 1D, the GNSS chipset 170 is located on a system on achip (SOC) substrate (SOCS) 190.

As described herein, various information can be extracted from the GNSSreceiver 1130, such as pseudorange information, Doppler ShiftInformation, Real Carrier Phase Measurement, WAAS and SBAS. Other typesof processing information output by the GNSS receiver 1130 can beignored.

A Cell device 100D's hardware architecture includes discreet physicallayout and interconnection of multiple chipsets for processing and forspecial purposes such as a GNSS chipset 170. In addition, newerarchitectures involve further integration of chipsets in the “system ona chip” (SoC) configuration. In this configuration, the GNSS chipset 170can still be a complete element capable of delivering a PVT (positionvelocity and time) solution. However in an embodiment, the pseudorangeinformation, carrier phase, and/or Doppler measurements, along with WAAScorrections if available, are extracted prior to further signalprocessing in the GNSS chipset 170 and are processed using differentalgorithms and corrections data for developing an improved accuracy PVTsolution. In so doing the deleterious effects of multipath and othererror sources may be minimized. Further the GNSS chipset 170 outputs areignored and not displayed when the external processing is employed andthe higher-accuracy PVT data is available.

FIG. 2 depicts a block diagram of a set of correction delivery optionsfor providing positioning information to a cellular device forextracting pseudorange information, according to one embodiment.Examples of a cellular device 200 include a cell phone, a non-voiceenabled cellular device, and a mobile hand-held GNSS receiver. Thecellular device may be mobile or stationary.

The cellular device 200 includes a bus 216, a satellite receiver 206, aGNSS receiver 107, an FM radio receiver 208, a processor 109, memory210, a cellular transceiver 211, a display 212, audio 213, Wi-Fitransceiver 214, IMU 215, image capturing device 240, and operatingsystem 160. Components 206, 107, 208, 109, 210, 211, 212, 213, 214, 215,and 240 are all connected with the buss 216.

In FIG. 2, a plurality of broadcast sources is used to convey data andmedia to a cellular device 200. As an example, cellular device 200 canreceive broadcast signals from communication satellites 201 (e.g.,two-way radio, satellite-based cellular such as the Inmarsat or Iridiumcommunication networks, etc.), global navigation satellites 202 whichprovide radio navigation signals (e.g., the GPS, GNSS, GLONASS, GALILEO,BeiDou, Compass, etc.), and terrestrial radio broadcast (e.g., FM radio,AM radio, shortwave radio, etc.)

A cellular device 200 can be configured with a satellite radio receiver206 coupled with a communication bus 216 for receiving signals fromcommunication satellites 201, a GNSS receiver 107 coupled with bus 216for receiving radio navigation signals from global navigation satellites202 and for deriving a position of cellular device 200 based thereon.Cellular device 200 further comprises an FM radio receiver 208 coupledwith bus 216 for receiving broadcast signals from terrestrial radiobroadcast 203. Other components of cellular device 200 comprise aprocessor 109 coupled with bus 216 for processing information andinstructions, a memory 210 coupled with bus 216 for storing informationand instructions for processor 109. It is noted that memory 210 cancomprise volatile memory and non-volatile memory, as well as removabledata storage media in accordance with various embodiments. Cellulardevice 200 further comprises a cellular transceiver 211 coupled with bus216 for communicating via cellular network 222. Examples of cellularnetworks used by cellular device 200 include, but are not limited toGSM: cellular networks, GPRS cellular networks, GDMA cellular networks,and EDGE cellular networks. Cellular device 200 further comprises adisplay 212 coupled with bus 216. Examples of devices which can be usedas display 212 include, but are not limited to, liquid crystal displays,LED-based displays, and the like. It is noted that display 212 can beconfigured as a touch screen device (e.g., a capacitive touch screendisplay) for receiving inputs from a user as well as displaying data.Cellular device 200 further comprises an audio output 213 coupled withbus 216 for conveying audio information to a user. Cellular device 200further comprises a Wi-Fi transceiver 214 and an inertial measurementunit (IMU) 215 coupled with bus 216. Wi-Fi transceiver 114 may beconfigured to operate on any suitable wireless communication protocolincluding, but not limited to WiFi, WiMAX, implementations of the IEEE802.11 specification, implementations of the IEEE 802.15.4 specificationfor personal area networks, and a short range wireless connectionoperating in the Instrument Scientific and Medical (ISM) band of theradio frequency spectrum in the 2400-2484 MHz range (e.g.,implementations of the Bluetooth® standard).

Improvements in GNSS/GPS positioning may be obtained by using referencestations with a fixed receiver system to calculate corrections to themeasured pseudoranges in a given geographical region. Since thereference station is located in a fixed environment and its location canbe determined very precisely via ordinary survey methods, a processorassociated with the Reference Station GNSS/GPS receivers can determinemore precisely what the true pseudoranges should be to each satellite inview, based on geometrical considerations. Knowing the orbital positionsvia the GPS almanac as a function of time enables this process, firstproposed in 1983, and widely adopted ever since. The difference betweenthe observed pseudorange and the calculated pseudorange for a givenReference station is called the pseudorange correction. A set ofcorrections for all the global navigation satellites 202 in view iscreated second by second, and stored, and made available as a service,utilizing GPS/GNSS reference stations 220 and correction services 221.The pseudoranges at both the cellular device 200 GPS receiver 107 andthose at the reference stations 220 are time-tagged, so the correctionsfor each and every pseudorange measurement can be matched to the localcell phone pseudoranges. The overall service is often referred to asDifferential GPS, or DGPS. Without any corrections, GNSS/GPS receiversproduce position fixes with absolute errors in position on the order of4.5 to 5.5 m per the GPS SPS Performance Standard, 4^(th) Ed. 2008. InFIG. 2, one or more correction services 221 convey these corrections viaa cellular network 222, or the Internet 223. Internet 223 is in turncoupled with a local Wi-Fi network 224 which can convey the correctionsto cellular device 200 via Wi-Fi transceiver 214. Alternatively,cellular network 222 can convey the corrections to cellular device 200via cellular transceiver 211. In some embodiments, correction services221 are also coupled with a distribution service 225 which conveys thecorrections to an FM radio distributor 226. FM radio distributor 226 canbroadcast corrections as a terrestrial radio broadcast 103. It should beappreciated that an FM signal is being described as a subset of possibleterrestrial radio broadcasts which may be in a variety of bands andmodulated in a variety of manners. In some embodiments, cellular device200 includes one or more integral terrestrial radio antennas associatedwith integrated terrestrial receivers; FM radio receiver 208 is oneexample of such a terrestrial receiver which would employ an integratedantenna designed to operate in the correct frequency band for receivinga terrestrial radio broadcast 103. In this manner, in some embodiments,cellular device 200 can receive the corrections via FM radio receiver208 (or other applicable type of integrated terrestrial radio receiver).In some embodiments, correction services 221 are also coupled with adistribution service 225 which conveys the corrections to a satelliteradio distributor 227. Satellite radio distributor 227 can broadcastcorrections as a broadcast from one or more communications satellites201. In some embodiments, cellular device 200 includes one or moreintegral satellite radio antennas associated with integrated satelliteradio receivers 206. Satellite radio receiver 206 is one example of sucha satellite receiver which would employ an integrated antenna designedto operate in the correct frequency band for receiving a corrections orother information broadcast from communication satellites 201. In thismanner, in some embodiments, cellular device 200 can receive thecorrections via satellite radio receiver 206.

Examples of a correction source that provides pseudorange correctionsare at least correction service 221, FM radio distribution 226, orsatellite radio distributor 227, or a combination thereof. According toone embodiment, a correction source is located outside of the cellulardevice 200.

Examples of image capturing device 240 are a camera, a video camera, adigital camera, a digital video camera, a digital camcorder, a stereodigital camera, a stereo video camera, a motion picture camera, and atelevision camera. The image capturing device 240 may use a lens or be apinhole type device.

The blocks that represent features in FIGS. 1A-2 can be arrangeddifferently than as illustrated, and can implement additional or fewerfeatures than what are described herein. Further, the featuresrepresented by the blocks in FIGS. 1A-2 can be combined in various ways.A cellular device 100, 200 (FIGS. 1A-3) can be implemented usingsoftware, hardware, hardware and software, hardware and firmware, or acombination thereof. Further, unless specified otherwise, variousembodiments that are described as being a part of the cellular device100, 200, whether depicted as a part of the cellular device 100, 200 ornot, can be implemented using software, hardware, hardware and software,hardware and firmware, software and firmware, or a combination thereof.Various blocks in FIGS. 1A-2 refer to features that are logic, such asbut not limited to, 150, 180B, 152, 152A, 152B, 151, 151A-151G, 170B,which can be; implemented using software, hardware, hardware andsoftware, hardware and firmware, software and firmware, or a combinationthereof.

The cellular device 100, 200, according to one embodiment, includeshardware, such as the processor 109, memory 210, and the GNSS chipset170. An example of hardware memory 210 is a physically tangible computerreadable storage medium, such as, but not limited to a disk, a compactdisk (CD), a digital versatile device (DVD), random access memory (RAM)or read only memory (ROM) for storing instructions. An example of ahardware processor 109 for executing instructions is a centralprocessing unit. Examples of instructions are computer readableinstructions for implementing at least the SUPL Client 101 that can bestored on a hardware memory 210 and that can be executed, for example,by the hardware processor 109. The SUPL client 101 may be implemented ascomputer readable instructions, firmware or hardware, such as circuitry,or a combination thereof.

Pseudorange Information

A GNSS receiver 107 (also referred to as a “receiver”), according tovarious embodiments, makes a basic measurement that is the apparenttransit time of the signal from a satellite to the receiver, which canbe defined as the difference between signal reception time, asdetermined by the receiver's clock, and the transmission time at thesatellite, as marked in the signal. This basic measurement can bemeasured as the amount of time shift required to align the C/A-codereplica generated at the receiver with the signal received from thesatellite. This measurement may be biased due to a lack ofsynchronization between the satellite and receiver clock because eachkeeps time independently. Each satellite generates a respective signalin accordance using a clock on board. The receiver generates a replicaof each signal using its own clock. The corresponding biased range, alsoknown as a pseudorange, can be defined as the transit time so measuredmultiplied by the speed of light in a vacuum.

There are three time scales, according to one embodiment. Two of thetime scales are the times kept by the satellite and receiver clocks. Athird time scale is a common time reference, GPS Time (GPST), also knownas a composite time scale that can be derived from the times kept byclocks at GPS monitor stations and aboard the satellites.

Let τ be the transit time associated with a specific code transition ofthe signal from a satellite received at time t per GPST. The measuredapparent range r, called pseudorange, can be determined from theapparent transmit time using equation 1 as follows:

measured pseudorange at (t)=c[arrival time at (t)−emission time at(t−τ)].  (Eq. 1)

Both t and τ are unknown, and can be estimated. In this discussion ofpseudoranges, measurements from a GPS satellite are dealt with in ageneric way to make the notation simple, making no reference to thesatellite ID or carrier frequency (L1 or L2).

Equations 2 and 3 depict how to relate the time scales of the receiverand the satellite clocks with GPST:

arrival time at (t)=t+receiver clock at (t)  (Eq. 2)

arrival time at (t−τ)=(t−τ)+satellite clock error at (t−τ)  (Eq. 3)

where receiver clock error represents the receiver 304's clock bias 303and satellite clock error represents the bias 301 in the satellite 305'sclock, and both the receiver clock and the satellite clock are measuredrelative to GPST 302, as shown in FIG. 3. Receiver clock error andsatellite clock error represent the amounts by which the satellite 305and receiver 304 clocks are advanced in relation to GPST. The satelliteclock error 301 is estimated by the Control Segment and specified interms of the coefficients of a quadratic polynomial in time. The valuesof these coefficients can be broadcast in the navigation message.

Accounting for the clock biases, the measured pseudorange (Eq. 1) can bewritten as indicated in equation 4:

PR(t)=c[t+receiver clock error at (t)−(t−τ+satellite clock error at(t−τ))]+miscellaneous errors at (t)=cτ+c[receiver clock errors at(t)−satellite clock error at (t−τ)]+miscellaneous errors at (t)  (Eq. 4)

where miscellaneous errors represent unmodeled effects, modeling error,and measurement error. The transmit time multiplied by the speed oflight in a vacuum can be modeled as satellite position at (t−τ).Ionosphere error and troposphere error reflect the delays associatedwith the transmission of the signal respectively through the ionosphereand the troposphere. Both ionosphere error and troposphere error arepositive.

For simplicity, explicitly reference to the measurement epoch t has beendropped, and the model has been rewritten for the measured pseudorangeas indicated in equation 5.

PR=r+[receiver clock error−satellite clock error]+ionosphereerror+troposphere error+miscellaneous errors  (Eq. 5)

where PR is the measured pseudorange, r is the true range from thereceiver to the satellite, receiver clock error is the differencebetween the receiver clock and the GPSTIME, satellite clock error is thedifference between the satellite clock and GPSTIME, GPSTIME isultimately determined at the receiver as part of the least squaredsolution determined by the least squares solution 171B so that all clockerrors can be resolved to some level of accuracy as part of the positiondetermination process, and miscellaneous errors include receiver noise,multipath and the like.

At least one source of error is associated with satellite positions inspace. The navigation message in the GPS signal contains Keplerianparameters which define orbital mechanics mathematics and, thus, thepositions of the satellites as a function of time. One component of WAASand RTX™ contains adjustments to these parameters, which form part ofthe constants used in solving for the position fix at a given time.Taking account of the corrections is well-known in the GPS positiondetermining arts.

Ideally, the true range r to the satellite is measured. Instead, what isavailable is PR, the pseudorange, which is a biased and noisymeasurement of r. The accuracy of an estimated position, velocity, ortime, which is obtained from these measurements, depends upon theability to compensate for, or eliminate, the biases and errors.

The range to a satellite is approximately 20,000 kilometers (km) whenthe satellite is overhead, and approximately 26,000 km when thesatellite is rising or setting. The signal transit time varies betweenabout 70 millisecond (ms) and 90 ms. The C/A-code repeats eachmillisecond, and the code correlation process essentially provides ameasurement of pseudo-transmit time modulo 1 ms. The measurement can beambiguous in whole milliseconds. This ambiguity, however, is easilyresolved if the user has a rough idea of his location within hundreds ofkilometers. The week-long P(Y)-code provides unambiguous pseudoranges.

The receiver clocks are generally basic quartz crystal oscillators andtend to drift. The receiver manufacturers attempt to limit the deviationof the receiver clock from GPST, and schedule the typicalonce-per-second measurements at epochs that are within plus or minus 1millisecond (ms) of the GPST seconds. One approach to maintaining thereceiver clock within a certain range of GPST is to steer the receiverclock ‘continuously.’ The steering can be implemented with software. Thesecond approach is to let the clock drift until it reaches a certainthreshold (typically 1 ms), and then reset it with a jump to return thebias to zero.

An example of pseudorange measurements with a receiver using the secondapproach shall now be described in more detail. Assume that there arepseudorange measurements from three satellites which rose about the sametime but were in different orbits. Assume that one comes overhead andstays in view for almost seven hours. Assume that the other two staylower in the sky and could be seen for shorter periods. There arediscontinuities common to all three sets of measurements due to theresetting of the receiver clock. A determination can be made as towhether the receiver clock is running fast or slow, and its frequencyoffset from the nominal value of 10.23 megahertz (MHz) can be estimated.

For more information on pseudorange information, refer to “GlobalPositioning Systems,” by Pratap Misra and Per Eng, Ganga-Jamuna Press,2001; ISBN 0-9709544-0-9.

Position Accuracy Improvements

The pseudorange information processing logic 150 can include varioustypes of logic for improving the position accuracy of the extractedpseudorange information, as described herein. Table 2, as describedherein, depicts various combinations of position accuracy improvementsfor improving extracted pseudorange information, according to variousembodiments. Table 3 also depicts various combinations of positionaccuracy improvements for improving extracted pseudorange information,according to various embodiments.

TABLE 3 Various Combinations of Position Accuracy Improvements forImproving Extracted Pseudorange Information Combi- nation IdentifierOperation Description Accuracy 1 620 (FIG. 6) Extracted Pseudorange 4-5meters (m) Information (EPI) 2 720A (FIG. 7A) EPI + WAAS approx. 1.7 m 3FIG. 7B EPI + reconstructed   <1 m CPI + WAAS 4 820A (FIG. 8A) EPI +DGPS   ~1 m 5 830A (FIG. 8A) EPI + DGPS + WAAS   <1 m 6 820B, 822B,EPI + reconstructed   <1 m 830B, 840B CPI + DGPS + WAAS FIG. 8B 7 820B,824B, EPI + real CPI +   <1 m 830B, 840B DGPS + WAAS (FIG. 8B) 8 920A(FIG. 9A) EPI + PPP   <1 m 9 930A (FIG. 9A) EPI + PPP + DGPS   <1 m 10FIG. 9B EPI + reconstructed   <1 m CPI + PPP + DGPS 11 1020 and 1030EPI + CPI + PPP <<1 m (FIG. 10) 12 1040 (FIG. 10) EPI + CPI + PPP +approx. 10 cm DGPS 13 EPI + RTK approx. 2-10 cm

Table 3 includes columns for combination identifier, operation,description, and accuracy. The combination identifier column indicatesan identifier for each combination of improvements. The operation columnspecifies operations of various flowcharts in FIGS. 6-10 for thecorresponding combination. The description column specifies variouscombinations of position accuracy improvements that can be applied toextracted pseudorange information (EPI) according to variousembodiments, where examples of position accuracy improvements include,but are not limited to, Wide Area Augmentation System (WAAS) pseudorangecorrections, real carrier phase smoothing (real CPI) information,reconstructed carrier phase smoothing information (reconstructed CPI),Differential GPS (DGPS) pseudorange corrections, and Precise PointPositioning (PPP) processing. The accuracy column specifies levels ofaccuracy provided by the corresponding combination.

Combination 1 is extracted pseudorange information without anyadditional improvements, which provides 4-5 meters of accuracy.Combination 1 is described in Table 3 to provide a comparison with theother combinations 2-13.

According to one embodiment, the SUPL client 101 can also include aposition-accuracy-improvement-determination-logic 180B for determiningthe one or more position accuracy improvements to apply to the extractedpseudorange information based on one or more factors such as cost,quality of service, and one or more characteristics of the cellulardevice. For example, different costs are associated with differentposition accuracy improvements. More specifically, extracted pseudorangeinformation, WAAS and Doppler information are typically free. There is alow cost typically associated with DGPS and real carrier phaseinformation. There is typically a higher cost associated with PPP.Therefore, referring to Table 3, according to one embodiment,combinations 1, 2, and 3 are typically free, combinations 4-7 typicallyare low cost, and combinations 8-12 are typically higher cost.

Various cellular devices have different characteristics that make themcapable of providing different types of position accuracy improvements.For example, one type of cellular device may be capable of providingWAAS but not be capable of providing Doppler information. In anotherexample, some types of cellular devices may be capable of providing DGPSbut not capable of providing PPP. In yet another example, differentactivities may require different levels of improvement. For example,some activities and/or people may be satisfied with 4-5 meters, othersmay be satisfied with 1.7 meters. Yet others may be satisfied with lessthan 1 meter, and still others may only be satisfied with 2 centimeters.Therefore, different users may request different levels of accuracy.

Table 4 depicts sources of the various position accuracy improvements,according to various embodiments.

TABLE 4 Sources of the Various Position Accuracy Improvements PositionAccuracy Improvement Name Source Pseudorange Information extracted fromGNSS chipset WAAS extracted from GNSS chipset or satellite broadcast viaInternet or radio delivery Real Carrier Phase extracted from GNSSchipset Information Doppler for reconstructing extracted from GNSSchipset carrier phase information Differential Global from a referencestation delivered by Positioning System dialing up, wired/wirelessinternet/intranet (DGPS) connection, or by receiving a broadcastsubcarrier modulation concatenated to an FM carrier frequency. DGPS canbe obtained at least from Trimble ® Real Time Kinematic from a referencestation (RTK)

The first column of Table 4 provides the name of the position accuracyimprovement. The second column of Table 4 specifies the source for thecorresponding position accuracy improvement.

According to various embodiments, a cellular device 100, 200 caninitially provide a position that is within 4-5 meters using, forexample, unimproved extracted pseudorange information and the positioncan continually be improved, using various position accuracyimprovements as described herein, as long as the antennae of thecellular device 100, 200 is clear of obstructions to receive variousposition accuracy improvements.

The following describes various position accuracy improvements andrelated topics in more detail.

Global Navigation Satellite Systems

A Global Navigation Satellite System (GNSS) is a navigation system thatmakes use of a constellation of satellites orbiting the earth to providesignals to a receiver, such as GNSS receiver 107, which estimates itsposition relative to the earth from those signals. Examples of suchsatellite systems are the NAVSTAR Global Positioning System (GPS)deployed and maintained by the United States, the GLObal NAvigationSatellite System (GLONASS) deployed by the Soviet Union and maintainedby the Russian Federation, and the GALILEO system currently beingdeployed by the European Union (EU).

Each GPS satellite transmits continuously using two radio frequencies inthe L-band, referred to as L1 and L2, at respective frequencies of1575.41 MHz and 1227.60 MHz. Two signals are transmitted on L1, one forcivil users and the other for users authorized by the Unites StatesDepartment of Defense (DoD). One signal is transmitted on L2, intendedonly for DoD-authorized users. Each GPS signal has a carrier at the L1and L2 frequencies, a pseudo-random number (PRN) code, and satellitenavigation data. Two different PRN codes are transmitted by eachsatellite: A coarse acquisition (C/A) code and a precision (P/Y) codewhich is encrypted for use by authorized users. A receiver, such as GNSSreceiver 107, designed for precision positioning contains multiplechannels, each of which can track the signals on both L1 and L2frequencies from a GPS satellite in view above the horizon at thereceiver antenna, and from these computes the observables for thatsatellite comprising the L1 pseudorange, possibly the L2 pseudorange andthe coherent L1 and L2 carrier phases. Coherent phase tracking impliesthat the carrier phases from two channels assigned to the same satelliteand frequency will differ only by an integer number of cycles.

Each GLONASS satellite transmits continuously using two radio frequencybands in the L-band, also referred to as L1 and L2. Each satellitetransmits on one of multiple frequencies within the L1 and L2 bandsrespectively centered at frequencies of 1602.0 MHz and 1246.0 MHz. Thecode and carrier signal structure is similar to that of NAVSTAR. A GNSSreceiver designed for precision positioning contains multiple channelseach of which can track the signals from both GPS and GLONASS satelliteson their respective L1 and L2 frequencies, and generate pseudorange andcarrier phase observables from these. Future generations of GNSSreceivers will include the ability to track signals from all deployedGNSSs.

Differential Global Positioning System (DGPS)

Differential GPS (DGPS) utilizes a reference station which is located ata surveyed position to gather data and deduce corrections for thevarious error contributions which reduce the precision of determining aposition fix. For example, as the GPS signals pass through theionosphere and troposphere, propagation delays may occur. Other factorswhich may reduce the precision of determining a position fix may includesatellite clock errors, GPS receiver clock errors, and satelliteposition errors (ephemerides). The reference station receivesessentially the same GPS signals as cellular devices 100, 200 which mayalso be operating in the area. However, instead of using the timingsignals from the GPS satellites to calculate its position, it uses itsknown position to calculate timing. In other words, the referencestation determines what the timing signals from the GPS satellitesshould be in order to calculate the position at which the referencestation is known to be. The difference in timing can be expressed interms of pseudorange lengths, in meters. The difference between thereceived GPS signals and what they optimally should be is used as anerror correction factor for other GPS receivers in the area. Typically,the reference station broadcasts the error correction to, for example, acellular device 100, 200 which uses this data to determine its positionmore precisely. Alternatively, the error corrections may be stored forlater retrieval and correction via post-processing techniques.

DGPS corrections cover errors caused by satellite clocks, ephemeris, andthe atmosphere in the form of ionosphere errors and troposphere errors.The nearer a DGPS reference station is to the receiver 107 the moreuseful the DGPS corrections from that reference station will be.

The system is called DGPS when GPS is the only constellation used forDifferential GNSS. DGPS provides an accuracy on the order of 1 meter or1 sigma for users in a range that is approximately in a few tens ofkilometers (kms) from the reference station and growing at the rate of 1m per 150 km of separation. DGPS is one type of Differential GNSS(DGNSS) technique. There are other types of DGNSS techniques, such asRTK and Wide Area RTK (WARTK), that can be used by high-precisionapplications for navigation or surveying that can be based on usingcarrier phase measurements. It should be appreciated that other DGNSSwhich may utilize signals from other constellations besides the GPSconstellation or from combinations of constellations. Embodimentsdescribed herein may be employed with other DGNSS techniques besidesDGPS.

A variety of different techniques may be used to deliver differentialcorrections that are used for DGNSS techniques. In one example, DGNSScorrections are broadcast over an FM subcarrier. U.S. Pat. No. 5,477,228by Tiwari et al. describes a system for delivering differentialcorrections via FM subcarrier broadcast method.

Real-Time Kinematic System

An improvement to DGPS methods is referred to as Real-time Kinematic(RTK). As in the DGPS method, the RTK method, utilizes a referencestation located at determined or surveyed point. The reference stationcollects data from the same set of satellites in view by the cellulardevice 100, 200 in the area. Measurements of GPS signal errors taken atthe reference station (e.g., dual-frequency code and carrier phasesignal errors) and broadcast to one or more cellular devices 100, 200working in the area. The one or more cellular devices 100, 200 combinethe reference station data with locally collected position measurementsto estimate local carrier-phase ambiguities, thus allowing a moreprecise determination of the cellular device 100, 200's position. TheRTK method is different from DGPS methods in that the vector from areference station to a cellular device 100, 200 is determined (e.g.,using the double differences method). In DGPS methods, referencestations are used to calculate the changes needed in each pseudorangefor a given satellite in view of the reference station, and the cellulardevice 100, 200, to correct for the various error contributions. Thus,DGPS systems broadcast pseudorange correction numbers second-by-secondfor each satellite in view, or store the data for later retrieval asdescribed above.

RTK allows surveyors to determine a true surveyed data point in realtime, while taking the data. However, the range of useful correctionswith a single reference station is typically limited to about 70 kmbecause the variable in propagation delay (increase in apparent pathlength from satellite to a receiver of the cellular device 100, 200, orpseudo range) changes significantly for separation distances beyond 70km. This is because the ionosphere is typically not homogeneous in itsdensity of electrons, and because the electron density may change basedon, for example, the sun's position and therefore time of day.

Thus for surveying or other positioning systems which must work overlarger regions, the surveyor must either place additional base stationsin the regions of interest, or move his base stations from place toplace. This range limitation has led to the development of more complexenhancements that have superseded the normal RTK operations describedabove, and in some cases eliminated the need for a base station GPSreceiver altogether. This enhancement is referred to as the “NetworkRTK” or “Virtual Reference Station” (VRS) system and method.

FIG. 4 depicts a flowchart 400 for determining an RTK position solution,according to one embodiment. At 410, the method begins. The inputs tothe method are reference station network or VRS corrections 412 and GNSSpseudorange plus carrier phase information from the cellular device 414.At 420, reference corrections and cellular device data are synchronizedand corrections are applied to the GNSS data for atmospheric models andso on. The output of 420 is synchronized GNSS data 422, which isreceived by operation 430. At 430, position, carrier phase ambiguitiesin floating point, and nuisance parameters are estimated. The output 432of 430 is user position plus carrier phase ambiguities in floatingpoint. Operation 440 receives the output 432 and produces improveduser-position estimates using the integer-nature of carrier phaseambiguities. The output 442 of 440 is an RTK position solution, whichcan be used according to various embodiments. The method ends at 450.

Network RTK

Network RTK typically uses three or more GPS reference stations tocollect GPS data and extract information about the atmospheric andsatellite ephemeris errors affecting signals within the network coverageregion. Data from all the various reference stations is transmitted to acentral processing facility, or control center for Network RTK. Suitablesoftware at the control center processes the reference station data toinfer how atmospheric and/or satellite ephemeris errors vary over theregion covered by the network.

The control center computer processor then applies a process whichinterpolates the atmospheric and/or satellite ephemeris errors at anygiven point within the network coverage area and generates a pseudorange correction comprising the actual pseudo ranges that can be used tocreate a virtual reference station. The control center then performs aseries of calculations and creates a set of correction models thatprovide the cellular device 100, 200 with the means to estimate theionospheric path delay from each satellite in view from the cellulardevice 100, 200, and to take account other error contributions for thosesame satellites at the current instant in time for the cellular device100, 200's location.

The cellular device 100, 200 is configured to couple a data-capablecellular telephone to its internal signal processing system. The useroperating the cellular device 100, 200 determines that he needs toactivate the VRS process and initiates a call to the control center tomake a connection with the processing computer.

The cellular device 100, 200 sends its approximate position, based onraw GPS data from the satellites in view without any corrections, to thecontrol center. Typically, this approximate position is accurate toapproximately 4-7 meters. The user then requests a set of “modeledobservables” for the specific location of the cellular device 100, 200.The control center performs a series of calculations and creates a setof correction models that provide the cellular device 100, 200 with themeans to estimate the ionospheric path delay from each satellite in viewfrom the cellular device 100, 200, and to take into account other errorcontributions for those same satellites at the current instant in timefor the cellular device 100, 200's location. In other words, thecorrections for a specific cellular device 100, 200 at a specificlocation are determined on command by the central processor at thecontrol center and a corrected data stream is sent from the controlcenter to the cellular device 100, 200. Alternatively, the controlcenter may instead send atmospheric and ephemeris corrections to thecellular device 100, 200 which then uses that information to determineits position more precisely.

These corrections are now sufficiently precise that the high performanceposition accuracy standard of 2-3 cm may be determined, in real time,for any arbitrary cellular device 100, 200's position. Thus a GPSenabled cellular device 100, 200's raw GPS data fix can be corrected toa degree that makes it behave as if it were a surveyed referencelocation; hence the terminology “virtual reference station.”

An example of a network RTK system in accordance with embodiments of thepresent invention is described in U.S. Pat. No. 5,899,957, entitled“Carrier Phase Differential GPS Corrections Network,” by Peter Loomis,assigned to the assignee of the present invention.

The Virtual Reference Station method extends the allowable distance fromany reference station to the cellular devices 100, 200. Referencestations may now be located hundreds of miles apart, and corrections canbe generated for any point within an area surrounded by referencestations. However, there are many construction projects where cellularcoverage is not available over the entire physical area underconstruction and survey.

Virtual Reference Stations

To achieve very accurate positioning (to several centimeters or less) ofa terrestrial mobile platform of a cellular device 100, 200, relative ordifferential positioning methods are commonly employed. These methodsuse a GNSS reference receiver located at a known position, in additionto the data from a GNSS receiver 107 on the mobile platform, to computethe estimated position of the mobile platform relative to the referencereceiver.

The most accurate known method uses relative GNSS carrier phaseinterferometry between the GNSS cellular device 100, 200's receiver andGNSS reference receiver antennas plus resolution of integer wavelengthambiguities in the differential phases to achieve centimeter-levelpositioning accuracies. These differential GNSS methods are predicatedon the near exact correlation of several common errors in the cellulardevice 100, 200 and reference observables. They include ionosphere andtroposphere signal delay errors, satellite orbit and clock errors, andreceiver clock errors.

When the baseline length between the mobile platform and the referencereceiver does not exceed 10 kilometers, which is normally considered ashort baseline condition, the ionosphere and troposphere signal delayerrors in the observables from the cellular device 100, 200 andreference receivers are almost exactly the same. These atmospheric delayerrors therefore cancel in the cellular device 100, 200's referencedifferential GNSS observables, and the carrier phase ambiguityresolution process required for achieving centimeter-level relativepositioning accuracy is not perturbed by them. If the baseline lengthincreases beyond 10 kilometers (considered a long baseline condition),these errors at the cellular device 100, 200 and reference receiverantennas become increasingly different, so that their presence in thecellular device 100, 200's-reference differential GNSS observables andtheir influence on the ambiguity resolution process increases. Ambiguityresolution on single cellular device 100, 200's reference receiverbaselines beyond 10 kilometers becomes increasingly unreliable. Thisattribute limits the precise resolution of a mobile platform withrespect to a single reference receiver, and essentially makes itunusable on a mobile mapping platform that covers large distances aspart of its mission, such as an aircraft.

A network GNSS method computes the estimated position of a cellulardevice 100, 200's receiver using reference observables from three ormore reference receivers that approximately surround the cellular device100, 200's receiver trajectory. This implies that the cellular device100, 200's receiver trajectory is mostly contained by a closed polygonwhose vertices are the reference receiver antennas. The cellular device100, 200's receiver 107 can move a few kilometers outside this polygonwithout significant loss of positioning accuracy. A network GNSSalgorithm calibrates the ionosphere and troposphere signal delays ateach reference receiver position and then interpolates and possiblyextrapolates these to the cellular device 100, 200's position to achievebetter signal delay cancellation on long baselines than could be hadwith a single reference receiver. Various methods of signal processingcan be used, however they all yield essentially the same performanceimprovement on long baselines.

Kinematic ambiguity resolution (KAR) satellite navigation is a techniqueused in numerous applications requiring high position accuracy. KAR isbased on the use of carrier phase measurements of satellite positioningsystem signals, where a single reference station provides the real-timecorrections with high accuracy. KAR combines the L1 and L2 carrierphases from the cellular device 100, 200 and reference receivers so asto establish a relative phase interferometry position of the cellulardevice 100, 200's antenna with respect to the reference antenna. Acoherent L1 or L2 carrier phase observable can be represented as aprecise pseudorange scaled by the carrier wavelength and biased by aninteger number of unknown cycles known as cycle ambiguities.Differential combinations of carrier phases from the cellular device100, 200 and reference receivers result in the cancellation of allcommon mode range errors except the integer ambiguities. An ambiguityresolution algorithm uses redundant carrier phase observables from thecellular device 100, 200 and reference receivers, and the knownreference antenna position, to estimate and thereby resolve theseambiguities.

Once the integer cycle ambiguities are known, the cellular device 100,200's receiver 107 can compute its antenna position with accuraciesgenerally on the order of a few centimeters, provided that the cellulardevice 100, 200 and reference antennas are not separated by more than 10kilometers. This method of precise positioning performed in real-time iscommonly referred to as real-time kinematic (RTK) positioning. Theseparation between a cellular device 100, 200 and reference antennasshall be referred to as “cellular device reference separation.”

The reason for the cellular device-reference separation constraint isthat KAR positioning relies on near exact correlation of atmosphericsignal delay errors between the cellular device 100, 200 and referencereceiver observables, so that they cancel in the cellular device 100,200's reference observables combinations (for example, differencesbetween cellular device 100, 200 and reference observables persatellite). The largest error in carrier-phase positioning solutions isintroduced by the ionosphere, a layer of charged gases surrounding theearth. When the signals radiated from the satellites penetrate theionosphere on their way to the ground-based receivers, they experiencedelays in their signal travel times and shifts in their carrier phases.A second significant source of error is the troposphere delay. When thesignals radiated from the satellites penetrate the troposphere on theirway to the ground-based receivers, they experience delays in theirsignal travel times that are dependent on the temperature, pressure andhumidity of the atmosphere along the signal paths. Fast and reliablepositioning requires good models of the spatio-temporal correlations ofthe ionosphere and troposphere to correct for these non-geometricinfluences.

When the cellular device 100, 200 reference separation exceeds 10kilometers, as maybe the case when the cellular device 100, 200 has aGNSS receiver 107 that is a LEO satellite receiver, the atmosphericdelay errors become de-correlated and do not cancel exactly. Theresidual errors can now interfere with the ambiguity resolution processand thereby make correct ambiguity resolution and precise positioningless reliable.

The cellular device 100, 200's reference separation constraint has madeKAR positioning with a single reference receiver unsuitable for certainmobile positioning applications where the mission of the mobile platformof the cellular device 100, 200 will typically exceed this constraint.One solution is to set up multiple reference receivers along the mobileplatform's path so that at least one reference receiver falls within a10 km radius of the mobile platform's estimated position.

Network GNSS methods using multiple reference stations of known locationallow correction terms to be extracted from the signal measurements.Those corrections can be interpolated to all locations within thenetwork. Network KAR is a technique that can achieve centimeter-levelpositioning accuracy on large project areas using a network of referenceGNSS receivers. This technique operated in real-time is commonlyreferred to as network RTK. The network KAR algorithm combines thepseudorange and carrier phase observables from the reference receiversas well as their known positions to compute calibrated spatial andtemporal models of the ionosphere and troposphere signal delays over theproject area. These calibrated models provide corrections to theobservables from the cellular device 100, 200's receiver, so that thecellular device 100, 200's receiver 107 can perform reliable ambiguityresolution on combinations of carrier phase observables from thecellular device 100, 200 and some or all reference receivers. The numberof reference receivers required to instrument a large project area issignificantly less than what would be required to compute reliablesingle baseline KAR solutions at any point in the project area. See, forexample, U.S. Pat. No. 5,477,458, “Network for Carrier PhaseDifferential GPS Corrections,” and U.S. Pat. No. 5,899,957, “CarrierPhase Differential GPS Corrections Network”. See also Liwen Dai et al.,“Comparison of Interpolation Algorithms in Network-Based GPSTechniques,” Journal of the Institute of Navigation, Vol. 50, No. 4(Winter 1003-1004) for a comparison of different network GNSSimplementations and comparisons of their respective performances.

A virtual reference station (VRS) network method is a particularimplementation of a network GNSS method that is characterized by themethod by which it computes corrective data for the purpose of cellulardevice 100, 200's position accuracy improvement. A VRS network methodcomprises a VRS corrections generator and a single-baseline differentialGNSS position generator such as a GNSS receiver 107 with differentialGNSS capability. The VRS corrections generator has as input data thepseudorange and carrier phase observables on two or more frequenciesfrom N reference receivers, each tracking signals from M GNSSsatellites. The VRS corrections generator outputs a single set of Mpseudorange and carrier phase observables that appear to originate froma virtual reference receiver at a specified position (hereafter calledthe VRS position) within the boundaries of the network defined by apolygon (or projected polygon) having all or some of the N referencereceivers as vertices. The dominant observables errors comprising areceiver clock error, satellite clock errors, ionosphere and tropospheresignal delay errors and noise all appear to be consistent with the VRSposition. The single-baseline differential GNSS position generatorimplements a single-baseline differential GNSS position algorithm, ofwhich numerous examples have been described in the literature. B.Hofmann-Wellenhof et al., Global Positioning System: Theory andPractice, 5th Edition, 1001 (hereinafter “Hofmann-Wellenhof [1001]”),gives comprehensive descriptions of different methods of differentialGNSS position computation, ranging in accuracies from one meter to a fewcentimeters. The single-baseline differential GNSS position algorithmtypically computes differences between the cellular device 100, 200 andreference receiver observables to cancel atmospheric delay errors andother common mode errors such as orbital and satellite clock errors. TheVRS position is usually specified to be close to or the same as theroving receiver's estimated position so that the actual atmosphericerrors in the cellular device 100, 200 receiver 107's observablesapproximately cancel the estimated atmospheric errors in the VRSobservables in the cellular device 100, 200's reference observablesdifferences.

The VRS corrections generator computes the synthetic observables at eachsampling epoch (typically once per second) from the geometric rangesbetween the VRS position and the M satellite positions as computed usingwell-known algorithms such as those given in IS-GPS-200G interfacespecification tilted “Naystar GPS Space Segment/Navigation UserInterfaces,” and dated 5 Sep. 2012. It estimates the typical pseudorangeand phase errors comprising receiver clock error, satellite clockerrors, ionospheric and tropospheric signal delay errors and noise,applicable at the VRS position from the N sets of M observablesgenerated by the reference receivers, and adds these to the syntheticobservables.

A network RTK system operated in real time requires each GNSS referencereceiver to transmit its observables to a network server computer thatcomputes and transmits the corrections and other relevant data to theGNSS cellular device 100, 200's receiver 107. The GNSS referencereceivers, plus hardware to assemble and broadcast observables, aretypically designed for this purpose and are installed specifically forthe purpose of implementing the network. Consequently, those receiversare called dedicated (network) reference receivers.

An example of a VRS network is designed and manufactured by TrimbleNavigation Limited, of Sunnyvale, Calif. The VRS network as delivered byTrimble includes a number of dedicated reference stations, a VRS server,multiple server-reference receiver bi-directional communicationchannels, and multiple server-cellular-device-bi-directional datacommunication channels. Each server-cellular device bi-directionalcommunication channel serves one cellular device 100, 200. The referencestations provide their observables to the VRS server via theserver-reference receiver bi-directional communication channels. Thesechannels can be implemented by a public network such as the Internet.The bi-directional server-cellular-device communication channels can beradio modems or cellular telephone links, depending on the location ofthe server with respect to the cellular device 100, 200.

The VRS server combines the observables from the dedicated referencereceivers to compute a set of synthetic observables at the VRS positionand broadcasts these plus the VRS position in a standard differentialGNSS (DGNSS) message format, such as one of the RTCM (Radio TechnicalCommission for Maritime Services) formats, an RTCA (Radio TechnicalCommission for Aeronautics) format or a proprietary format such as theCMR (Compact Measurement Report) or CMR+ format which are messagingsystem communication formats employed by Trimble Navigation Limited.Descriptions for numerous of such formats are widely available. Forexample, RTCM Standard 10403.1 for DGNSS Services—Version 3, publishedOct. 26, 2006 (and Amendment 2 to the same, published Aug. 31, 2007) isavailable from the Radio Technical Commission for Maritime Services,1800 N. Kent St., Suite 1060, Arlington, Va. 22209. The syntheticobservables are the observables that a reference receiver located at theVRS position would measure. The VRS position is selected to be close tothe cellular device 100, 200's estimated position so that the cellulardevice 100, 200's VRS separation is less than a maximum separationconsidered acceptable for the application. Consequently, the cellulardevice 100, 200 receiver 107 must periodically transmit its approximateposition to the VRS server. The main reason for this particularimplementation of a real-time network RTK system is compatibility withRTK survey GNSS receivers that are designed to operate with a singlereference receiver.

Descriptions of the VRS technique are provided in U.S. Pat. No.6,324,473 of (hereinafter “Eschenbach”) (see particularly col. 7, line21 et seq.) and U.S. Patent application publication no. 2005/0064878, ofB. O'Meagher (hereinafter “O'Meagher”), which are assigned to TrimbleNavigation Limited; and in H. Landau et al., Virtual Reference Stationsversus Broadcast Solutions in Network RTK, GNSS 2003 Proceedings, Graz,Austria (2003).

The term “VRS”, as used henceforth in this document, is used asshorthand to refer to any system or technique which has thecharacteristics and functionality of VRS described or referenced hereinand is not necessarily limited to a system from Trimble Navigation Ltd.Hence, the term “VRS” is used in this document merely to facilitatedescription and is used without derogation to any trademark rights ofTrimble Navigation Ltd. or any subsidiary thereof or other relatedentity.

Precise Positioning Point (PPP)

Descriptions of a Precise Point Positioning (PPP) technique are providedin U.S. Patent application publication 20110187590, of Leandro, which isassigned to Trimble Navigation Limited. Trimble Navigation Limited hascommercialized a version of PPP corrections which it calls RTX™. PPPcorrections can be any collection of data that provides corrections froma satellite in space, clock errors, ionosphere or troposphere, or acombination thereof. According to one embodiment, PPP corrections can beused in instead of WAAS or RTX™.

The term Precise Point Positioning (PPP), as used henceforth in thisdocument, is used as shorthand to refer to any system or technique whichhas the characteristics and functionality of PPP described or referencedherein and is not necessarily limited to a system from TrimbleNavigation Ltd. Hence, the term “PPP” is used in this document merely tofacilitate description and is used without derogation to any trademarkrights of Trimble Navigation Ltd. or any subsidiary thereof or otherrelated entity. Techniques for generating PPP corrections are well knownin the art. In general, a PPP system utilizes a network (which may beglobal) of GNSS reference receivers tracking navigation satellites suchas GPS and GLONASS satellites and feeding data back to a centralizedlocation for processing. At the centralized location, the precise orbitsand precise clocks of all of the tracked navigation satellites aregenerated and updated in real time. A correction stream is produced bythe central location; the correction stream contains the orbit and clockinformation. This correction stream is broadcast or otherwise providedto GNSS receivers, such as a GNSS receiver 107, in the field(conventionally by satellite service or cellular link) Correctionsprocessors in the GNSS receivers utilize the corrections to producecentimeter level positions after a short convergence time (e.g., lessthan 30 minutes). A main difference between PPP and VRS is that PPPnetworks of reference receivers are typically global while VRS networksmay be regional or localized with shorter spacing between the referencestations in a VRS network.

Wide Area Augmentation System (WAAS)

Wide Area Augmentation System (WAAS) corrections are corrections ofsatellite position and their behavior. WAAS was developed by the FederalAviation Administration (FAA). WAAS includes a network of referencestations that are on the ground located in North America and Hawaii. Thereference stations transmit their respective measurements to masterstations which queue their respective received measurements. The masterstations transmit WAAS corrections to geostationary WAAS satellites,which in turn broadcast the WAAS corrections back to earth wherecellular devices 100, 200 that include WAAS-enabled GPS receivers canreceive the broadcasted WAAS corrections. According to one embodiment,the GNSS receiver 107 is a WAAS-enabled GPS receiver. The WAAScorrections can be used to improve the accuracy of the respectivecellular devices 100, 200′ positions, for example, by applying the WAAScorrections to extracted pseudoranges. WAAS operation and implementationis well known in the art.

Real Carrier Phase Information

According to one embodiment, a GNSS chipset 170 provides real carrierphase information (also referred to as “actual carrier phaseinformation”). The cellular device 100, 200 can extract real carrierphase information from the GNSS chipset 170 in a manner similar toextracting pseudorange information from the GNSS chipset 170, where theextracted carrier phase information is for use elsewhere in the cellulardevice 100, 200 outside of the GNSS chipset 170 as described herein, forexample, with flowchart 600 of FIG. 6.

FIG. 5A is a flowchart 500A of a method for performing a carrier phasesmoothing operation using real carrier phase information, according toone embodiment. In various embodiments, carrier phase smoothing logic152 may be implemented by either a range domain hatch filter, or aposition domain hatch filter, or by any of other implementations knownin the literature. The range domain hatch filter method is described inU.S. Pat. No. 5,471,217 by Hatch et al., entitled “Method and Apparatusfor Smoothing Coded Measurements in a Global Positioning SystemReceiver,” filed Feb. 1, 1993, and the Hatch paper entitled “Thesynergism of GPS code and carrier measurements,” published in theProceedings of the Third International Geodetic symposium on satelliteDoppler Positioning, New Mexico, 1982: 1213-1232. See also p 45 of theMaster's Thesis by Sudha Neelima Thipparthi entitled “ImprovingPositional Accuracy using Carrier Smoothing Techniques in InexpensiveGPS Receivers,” MSEE thesis, New Mexico State University, Las Cruces, N.Mex., February 2004.

The filtering/processing described herein lies in the family of errorsin pseudorange processing that affect code and carrier measurements inthe same way. In various embodiments, the code phase pseudorangemeasurements are “disciplined” by subtracting out a more constantequivalent pseudorange-like distance measurement derived from thecarrier phase. Next, a filtering on the net subtracted signal isperformed which allows various embodiments to eliminate multipathinduced errors in the raw, and corrected, pseudorange data. This methoddoes not deal with ionospheric effects, according to one embodiment.

In operation 501A of FIG. 5A, extracted pseudorange information andcarrier phases for a first epoch are collected. In one embodiment, theseextracted pseudorange information and carrier phases are received atcarrier phase smoothing logic 152 from the GNSS receiver 107.

In operation 502A of FIG. 5A, pseudorange corrections are collected andapplied to the first set of extracted pseudoranges collected inoperation 501A. In one embodiment, these corrections themselves may besmoothed at the reference receiver (e.g., at GPS/GNSS reference stations220) so that the delivered pseudorange corrections themselves are lessnoisy. Smoothing the pseudorange corrections derived at the GPS/GNSSreference stations 220 using the same carrier phase method of flowchart500A can vastly improve the quality of the delivered pseudorangecorrections delivered to cellular device 100, 200 for use by a positiondetermination processor (e.g., GNSS receiver 107 or pseudorangeinformation processing logic 150). Such corrected pseudoranges that arealso smoothed may be used by the cellular device 100, 200 and fetched ifavailable.

In operation 503A of FIG. 5A, delta carrier phase measurements for thesame epoch are created using real carrier phase information. Inaccordance with various embodiments, this replicates creating a seconddistance measurement, similar to the reconstructed carrier phaseinformation, based on integrated Doppler Shift.

In operation 504A of FIG. 5A, the delta carrier phase measurements aresubtracted from the corrected extracted pseudoranges. In accordance withvarious embodiments, this provides a fairly constant signal for thatepoch and is equivalent to the corrected extracted pseudorange at thestart of the integration interval. In accordance with variousembodiments, this is referred to as a “disciplining” step that smoothesout the corrected extracted pseudorange signal and therefore reduces theinstant errors in the later-computed position fixes.

In operation 505A of FIG. 5A, the signal is filtered after thesubtraction of operation 504A to reduce noise. In accordance with oneembodiment, this is performed by averaging the carrier phase“yardsticks” over a series of epochs.

In operation 506A of FIG. 5A, the delta carrier phase measurements fromthe real carrier phase processing operation is added back into thefiltered signal of operation 505A.

In operation 507A of FIG. 5A, the new filtered and corrected extractedpseudorange signal is processed, for example, at the pseudorangeinformation processing logic 150, to derive a position fix 172B.

Reconstructing Carrier Phase Information based on Doppler Shift

Carrier Phase Information can be reconstructed (referred to herein as“reconstructed carrier phase”) based on Doppler Shift. Doppler Shift isthe change in frequency of a periodic event (also known as a “wave”)perceived by an observer that is moving relative to a source of theperiodic event. For example, Doppler shift refers to the change inapparent received satellite signal frequency caused by the relativemotion of the satellites as they either approach the cellular device100, 200 or recede from it. Thus any measurement of Doppler frequencychange is similar to differentiating carrier phase. It is thereforepossible to reconstruct the carrier phase by integrating the Dopplershift data. In an embodiment, the GNSS chipset 170 of GNSS receiver 107may provide Doppler information it determines through other means. ThisDoppler frequency shift information or “Doppler” may be collected ateach GPS timing epoch (e.g., one second) and integrated over a sequenceof the one-second epochs, to produce a model of carrier phase. ThisDoppler-derived carrier phase model may be substituted for the realcarrier phase data, and used in the same manner as shown in the flowchart for carrier phase smoothing of FIG. 5A. Doppler Shift signalprocessing is well known in the art.

FIG. 5B is a flowchart 500B of a method for generating reconstructedcarrier phase information (also referred to as a “Doppler-derivedcarrier phase model”) based on Doppler Shift, according to oneembodiment. In accordance with one embodiment, method of flowchart 500Bis implemented at GPS/GNSS reference stations and the modeled carrierphase is provided to cellular device 100, 200 via one of thecommunication networks described above.

In operation 501B of FIG. 5B, Doppler information from a GNSS receiver107 of a GNSS chipset 170 is received bypseudorange-carrier-phase-smoothing-logic 152.

In operation 502B of FIG. 5B, a series of Doppler information isintegrated. As described above, Doppler frequency shift information maybe collected at each GPS timing epoch (e.g., one second) and stored foruse in producing a model of carrier phase.

In operation 503B of FIG. 5B, a model of carrier phase is created basedon integrated Doppler information. As discussed above with reference tooperation 502B, a series of Doppler information for a plurality oftiming epochs is integrated. In one embodiment, this Doppler informationis integrated over a sequence of the one-second epochs, to produce amodel of carrier phase. The sequence may include 10-100 epochs, orseconds. The model of carrier phase smoothing is used as thereconstructed carrier phase information.

In operation 504B of FIG. 5B, the modeled carrier phase, which is alsoreferred to as “reconstructed carrier phase information”, is supplied topseudorange-carrier-phase-smoothing-logic 152. As described above,method of flowchart 500B can be implemented at GPS/GNSS referencestations 220 and the reconstructed carrier phase information can then bebroadcast to cellular device 100, 200.

Method of Extracting Pseudorange Information

FIG. 6 depicts a flowchart 600 of a method of extracting pseudorangeinformation using a cellular device, according to one embodiment.

At 610, the method begins.

At 620, the cellular device 100, 200 accesses the GNSS chipset 170embedded within the cellular device 100, 200 where the GNSS chipset 170calculates pseudorange information for use by the GNSS chipset 170. Forexample, the GNSS receiver 107 can perform GPS measurements to deriveraw measurement data for a position of the cellular device 100. The rawmeasurement data provides an instant location of the cellular device100. The GNSS chipset 170 calculates pseudorange information that is foruse by the GNSS chipset 170. According to one embodiment, the rawmeasurement data is the pseudorange information that will be extracted.Examples of pseudorange information are uncorrected pseudorangeinformation, differential GNSS corrections, high precision GNSSsatellite orbital data, GNSS satellite broadcast ephemeris data, andionospheric projections.

A chipset accessor logic 141, according to one embodiment, is configuredfor accessing the GNSS chipset 170. According to one embodiment, thechipset accessor logic 141 is a part of an SUPL client 101.

The pseudorange information can be obtained from the processor 172 ofthe GNSS receiver 107 using a command. The GNSS chipset 170 may bedesigned, for example, by the manufacturer of the GNSS chipset 170, toprovide requested information, such as pseudorange information, inresponse to receiving the command. The pseudorange information may beextracted from the GNSS chipset 170 using the command that themanufacturer has designed the GNSS chipset 170 with. For example,according to one embodiment, the GNSS chipset 170 is accessed using anoperation that is a session started with a message that is an improvedaccuracy Secure User Platform Location (SUPL) start message or a highprecision SUPL INIT message. According to one embodiment, the message isa custom command that is specific to the GNSS chipset 170 (also referredto as “a GNSS chipset custom command”) and the improved accuracy SUPLclient 101 can access to the raw measurements of the GNSS chipset 170.

Examples of chipset manufacturers include Qualcomm, Texas Instruments,FastraX, Marvel, SIRF, Trimble, SONY, Furuno, Nemerix, Phillips, andXEMICS, to name a few.

At 630, the cellular device 100, 200 extracts the pseudorangeinformation from the GNSS chipset 170 for use elsewhere in the cellulardevice 100, 200 outside of the GNSS chipset 170. For example,pseudorange information extractor logic 142 may be associated with aworker thread of the SUPL client 101. The worker thread associated withthe SUPL client 101 can monitor the raw measurements delivered by theGNSS chipset 170 into the GNSS chipset 170's memory buffers, cache theraw measurements and use the raw measurements to determine a positionfix. The pseudorange information extractor logic 142 and the pseudorangeinformation processing logic 150 can be associated with the workerthread. For example, the pseudorange information extractor logic 142 cancache the raw measurements and the pseudorange information processinglogic 150 can determine the location.

According to one embodiment, the raw measurement data is the pseudorangeinformation that is extracted. According to one embodiment, the rawmeasurement data is pseudorange information that is calculated by theGNSS chipset 170 and is only for use by the GNSS chipset 170.

According to one embodiment, a determining position fix logic 170B mayperform a least squares solution171B on the extracted pseudorangeinformation prior to transmitting the output to the pseudorangeinformation bridger logic 143. According to another embodiment, theextracted pseudorange information is improved using various embodimentsdescribed in FIGS. 7A-10 prior to performing a least squaressolution171B, as will be described herein.

Methods of Improving Position Accuracy of Extracted PseudorangeInformation

The extracted pseudorange information without further improvements canbe used to provide an instant location, as described herein. Theextracted pseudorange information can be improved by applying positionaccuracy improvements that include, but are not limited to, thosedepicted in Tables 2 and 3. The instant location or the improvedlocation can be communicated to location manager logic 161, as discussedherein, that displays the instant location or the improved location withrespect to a map.

FIG. 7A depicts a flowchart 700A of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 710A, the method begins.

At 720A, the pseudorange-correction-logic 151 provides Wide AreaAugmentation System (WAAS) corrected pseudoranges by applying WAAScorrections to the extracted pseudorange information. For example, thepseudorange-correction-logic 151 receives the extracted pseudorangeinformation that was extracted from the GNSS chipset 170 at 630 of FIG.6. The cellular device 100, 200 receives the WAAS corrections, asdescribed herein, and provides the WAAS corrections to thepseudorange-correction-logic 151. The pseudorange-correction-logic 151provides Wide Area Augmentation System (WAAS) corrected pseudoranges byapplying the received WAAS corrections to the extracted pseudorangeinformation.

At 730A the method ends.

FIG. 7B depicts a flowchart 700B of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 710B, the method begins.

At 720B, the pseudorange-carrier-phase-smoothing-logic 152 providessmoothed pseudorange information by performing pseudorange smoothing onthe extracted pseudorange information based on carrier phaseinformation. For example, if real carrier phase information isavailable, the cellular device 100, 200 can extract it as discussedherein. Otherwise, the cellular device 100, 200 can derive reconstructedcarrier phase information as described herein and provide thereconstructed carrier phase information to thepseudorange-carrier-phase-smoothing-logic 152. Thepseudorange-carrier-phase-smoothing-logic 152 can receive the extractedpseudorange information that was extracted from the GNSS chipset 170 at630 of FIG. 6. The pseudorange-carrier-phase-smoothing-logic 152 canapply either the real carrier phase information or the real carrierphase information to the extracted pseudorange information to providesmoothed pseudorange information.

At 730B, a position fix is determined based on the smoothed pseudorangeinformation and WAAS pseudorange corrections. For example, thepseudorange-correction-logic 151 receives the smoothed pseudorangeinformation and receives WAAS pseudorange corrections and determines aposition fix based on the smoothed pseudorange information and the WAASpseudorange corrections.

At 740B, the method ends.

According to one embodiment, a determining position fix logic 170B mayperform a least squares solution 171B on the output of flowchart 700Aand 700B prior to transmitting the output to the pseudorange informationbridger logic 143.

FIG. 8A depicts a flowchart 800A of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 810A, the method begins.

At 820A, the pseudorange-correction-logic 151 provides DifferentialGlobal Positioning System (DGPS) corrected pseudoranges by applying DGPScorrections to the extracted pseudorange information.

For example, the pseudorange-correction-logic 151 receives the extractedpseudorange information that was extracted from the GNSS chipset 170 at630 of FIG. 6. The cellular device 100, 200 receives the DGPScorrections as described herein and provides the DGPS corrections to thepseudorange-correction-logic 151. The pseudorange-correction-logic 151provides Differential Global Positioning System (DGPS) correctedpseudoranges by applying the received DGPS corrections to the extractedpseudorange information.

At 830A, the pseudorange-correction-logic 151 provides WAAS-DGPScorrected pseudoranges by applying Wide Area Augmentation System (WAAS)to the DGPS corrected pseudoranges.

For example, the pseudorange-correction-logic 151 accesses the DGPScorrected pseudoranges determined at 820A of FIG. 8A. The cellulardevice 100, 200 receives the WAAS corrections as described herein andprovides the WAAS corrections to the pseudorange-correction-logic 151.The pseudorange-correction-logic 151 provides WAAS-DGPS correctedpseudoranges by applying Wide Area Augmentation System (WAAS) to theDGPS corrected pseudoranges.

At 840A, the method ends.

FIG. 8B depicts a flowchart 800B of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 810B, the method begins.

At 820B, a position determination decision is made as to whether toproceed to 822B or 824B. For example, at operation 820B, the positionaccuracy improvement determination logic 180B can determine whether toproceed to 822B or 824B as discussed herein.

At 830B, DGPS corrected smoothed pseudoranges are provided by applyingcorrections to the smoothed pseudorange information. For example, thepseudorange-correction-logic 151 can provide DGPS corrected smoothedpseudoranges by applying DGPS corrections to the smoothed pseudorangesdetermined at either 822B or 824B.

At 840B, WAAS-DGPS corrected smoothed pseudoranges are provided byapplying WAAS to the DGPS corrected smoothed pseudoranges. For example,the pseudorange-correction-logic 151 can provide WAAS-DGPS correctedsmoothed pseudoranges by applying WAAS corrections to the DGPS correctedsmoothed pseudoranges.

At 850B, the method ends.

According to one embodiment, a determining position fix logic 170B mayperform a least squares solution 171B on the output of flowcharts 800Aor 800B prior to transmitting the output to the pseudorange informationbridger logic 143.

FIG. 9A depicts a flowchart 900A of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 910A, the method begins.

At 920A, DGPS corrected pseudoranges are determined by applying DGPSpseudorange corrections to extracted pseudorange information. Forexample, the pseudorange-correction-logic 151 receives extractedpseudorange information from the pseudorange information extractor logic142 and applies the DGPS pseudorange corrections to the extractedpseudorange information.

At 930A, the pseudorange-correction-logic 151 can determine a positionfix based on the DGPS corrected pseudoranges and PPP corrections.

At 940A, the method ends.

FIG. 9B depicts a flowchart 900B of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 910B, the method begins.

At 920B, smoothed pseudorange information is provided by performingpseudorange smoothing on the extracted pseudorange information usingcarrier phase information. For example, thepseudorange-carrier-phase-smoothing-logic 152 provides smoothedpseudorange information by performing pseudorange smoothing on theextracted pseudorange information, which can be obtained as discussedherein, based on carrier phase information. If real carrier phaseinformation is available, the cellular device 100, 200 can extract thereal carrier phase information, as discussed herein. Otherwise, thecellular device 100, 200 can derive reconstructed carrier phaseinformation, as described herein, and provide the reconstructed carrierphase information to the pseudorange-carrier-phase-smoothing-logic 152.

At 930B, DGPS corrected smoothed pseudoranges are provided by applyingDGPS pseudorange corrections to the smoothed pseudorange information.For example, the pseudorange-correction-logic 151 can receive thesmoothed pseudorange information from thepseudorange-carrier-phase-smoothing-logic 152. Thepseudorange-correction-logic 151 can determine the corrected smoothedpseudoranges by applying DGPS pseudorange corrections to the smoothedpseudorange information.

At 940B, a position fix can be determined based on the DGPS correctedsmoothed pseudoranges and PPP corrections. For example, thepseudorange-correction-logic 151 can determine a position fix based onthe DGPS corrected smoothed pseudoranges and PPP corrections.

At 950B, the method ends.

According to one embodiment, a determining position fix logic 170B mayperform a least squares solution 171B on the output of flowcharts 900Aand 900B prior to transmitting the output to the pseudorange informationbridger logic 143.

FIG. 10 depicts a flowchart 1000 of a method of improving the positionaccuracy using one or more position accuracy improvements, according toone embodiment.

At 1010, the method begins.

At 1020, the pseudorange-carrier-phase-smoothing-logic 152 smoothes theextracted pseudorange information based on carrier phase smoothing. Forexample, the pseudorange-carrier-phase-smoothing-logic 152 receivesextracted pseudorange information from the pseudorange informationextractor logic 142 and receives carrier phase information, which may beeither real carrier phase information or reconstructed carrier phaseinformation, as described herein. Thepseudorange-carrier-phase-smoothing-logic 152 smoothes the extractedpseudorange information based on carrier phase smoothing.

At 1030, the PPP logic 151C provides a smoothed improved accuracyposition fix by performing Precise Point Positioning (PPP) processing onthe smoothed extracted pseudorange information. For example, the PPPlogic 151C receives the smoothed extracted pseudorange informationprovided by the pseudorange-carrier-phase-smoothing-logic 152 at 1020.The PPP logic 151C provides a smoothed improved accuracy position fix byperforming Precise Point Positioning (PPP) processing on the smoothedextracted pseudorange information

At 1040, the pseudorange-correction-logic 151 can optionally correct thesmoothed improved accuracy position fix by applying Differential GlobalPositioning System (DGPS) corrections to the smoothed improved accuracyposition fix. For example, pseudorange-correction-logic 151 receives thesmoothed improved accuracy position fix provided by the PPP logic 151Cat 1030. The pseudorange-correction-logic 151 receives DGPS correctionsas described herein. The pseudorange-correction-logic 151 corrects thesmoothed improved accuracy position fix by applying Differential GlobalPositioning System (DGPS) corrections to the smoothed improved accuracyposition fix, thus, providing a corrected smoothed improved accuracyposition fix. Operation 1040 is optional, according to one embodiment.

At 1050, the method ends.

According to one embodiment, a determining position fix logic 170B mayperform a least squares solution 171B on the output of flowchart 1000prior to transmitting the output to the pseudorange information bridgerlogic 143.

FIG. 11 depicts a flowchart 1100 of a method of accessing and processingextracted pseudorange information, according to one embodiment.

At 1110, various types of information can be accessed. Examples ofaccessing are extracting 1112 information and receiving 1114information. Unsmoothed uncorrected pseudorange information can beextracted at 1112A, WAAS corrections can be extracted at 1112B, SBAScorrections can be extracted at 1112E, Doppler shift can be extracted at1112C, and carrier phase measurements can be extracted at 1112D.“Accessing” and “obtaining” can be used interchangeably. Table 1 depictstypes of information that can be extracted at operation 1112 from theGNSS chipset 170 and types of information that are received at operation1114 instead of being extracted. However, various embodiments are notlimited to the types of information that can be extracted or receiveddepicted in Table 1.

The received or extracted information or a combination thereof, can beprocessed at 1120.

What or whether to apply position accuracy improvements can bedetermined at 1160, for example, by the position accuracy improvementdetermination logic 180B. Examples of position accuracy improvements arereal carrier phase information, reconstructed carrier phase information,WAAS, SBAS, DGPS, PPP, RTK, VRS and RTX™ corrections. The determinationlogic 180B can determine whether one or more and in what order logics152A, 152B, 151A-151F are performed, according to one embodiment. Tables2 and 3 are examples of carrier phase information or corrections or acombination thereof, that the position accuracy improvementdetermination logic 180B may determine, as discussed herein.

The information can be smoothed at 1130. Examples of smoothing 1130 arereal carrier phase smoothing 1132 and reconstructed carrier phasesmoothing 1134.

Either unsmoothed information or smoothed information can be correctedat 1140. For example, unsmoothed information from 1110 or smoothedinformation from 1130 can be corrected at 1140. Examples of correctingare SBAS correcting 1140G, WAAS correcting 1140A, DGPS correcting 1140B,PPP correcting 1140C, RTK correcting 1140D, VRS correcting 1140E, andRTX correcting 1140F. The smoothed information or unsmoothed informationcan be corrected using one or more of operations 1140A-1140G. Accordingto one embodiment, WAAS correcting 1140A is an example of SBAScorrecting 1140G.

Unsmoothed information from 1110, smoothed information from 1112,corrected unsmoothed information from 1140 or corrected smoothedinformation from 1140 can be used to determine a position fix 172B at1150, for example, by performing a least squares solution 171B at 1152.The output of flowchart 1100 is a position fix 172B. Table 2 and Table 3depict combinations of information that result in a position fix 172B,according to various embodiments.

According to one embodiment, accessing 1110, extracting 1112, extractingpseudorange information 1112A, extracting SBAS 1112E, extracting WAAS1112B, extracting Doppler 1112C, extracting carrier phase measurement1112D, receiving 1114, smoothing 1130, correcting 1140, determining aposition fix 1150, and performing a least squares solution 1152 can beperformed respectively by logic 110B, 142, 112B-5, 112B-2, 112B-3,112B-4, 114B, 150, 152, 151, and 170B. Real carrier phase smoothing1132, reconstructed carrier phase smoothing 1134, correcting 1140A-1140Gcan be performed respectively by logic 152A, 152B, 151A-151E, 151F,151G.

Any one or more of 1112, 1112A-1112E, 1132, 1134, 1140A-1140G can beperformed. Further, any one or more of 1112, 1112A-1112E, 1112B, 1112C,1112E, 1132, 1134, 1140A-1140G can be performed in various orders.Various embodiments are not limited to just the combinations that aredescribed herein.

According to one embodiment, a Global Navigation Satellite System (GNSS)chipset embedded within the cellular device is accessed at 620 (FIG. 6)where the GNSS chipset calculates pseudorange information for use by theGNSS chipset. The pseudorange information is extracted at 640 (FIG. 6),112 (FIG. 11) from the GNSS chipset for use elsewhere in the cellulardevice outside of the GNSS chipset. The accessing 620 and the extracting640, 1112A can be performed by the cellular device 100, 200 thatincludes hardware 180.

The extracted pseudorange information can be smoothed at 1130. Thesmoothing 1130 can be based on reconstructed carrier phase informationor real carrier phase information. The smoothed pseudorange informationcan be corrected at 1140. Examples of the types of correctedpseudoranges are Wide Area Augmentation System (WAAS), DifferentialGlobal Positioning System (DGPS), Precise Point Positioning (PPP), andReal Time Kinematic (RTK). Pseudorange corrections can be accessed 1110.The corrected pseudorange information can be derived, for example at1140, by applying the pseudorange corrections to the extractedpseudorange information.

FIGS. 4-11 depict flowcharts 400-1100, according to one embodiment.Although specific operations are disclosed in flowcharts 400-1100, suchoperations are exemplary. That is, embodiments of the present inventionare well suited to performing various other operations or variations ofthe operations recited in flowcharts 400-1100. It is appreciated thatthe operations in flowcharts 400-1100 may be performed in an orderdifferent than presented, and that not all of the operations inflowcharts 400-1100 may be performed.

The operations depicted in FIGS. 4-11 transform data or modify data totransform the state of a cellular device 100, 200. For example, byextracting pseudorange information from a GNSS chipset 170 for useelsewhere, the state of the cellular device 100, 200 is transformed froma cellular device that is not capable of determining a position fixitself into a cellular device that is capable of determining a positionfix itself. In another example, operations depicted in flowcharts400-1100 transform the state of a cellular device 100, 200 from notbeing capable of providing an improved accuracy position fix to becapable of providing an improved accuracy position fix.

The above illustration is only provided by way of example and not by wayof limitation. There are other ways of performing the method describedby flowcharts 400-1100.

The operations depicted in FIGS. 4-11 can be implemented as computerreadable instructions, hardware or firmware. According to oneembodiment, hardware associated with a cellular device 100, 200 canperform one or more of the operations depicted in FIGS. 4-11.

Example GNSS Receiver

With reference now to FIG. 12, a block diagram is shown of an embodimentof an example GNSS receiver which may be used in accordance with variousembodiments described herein. In particular, FIG. 12 illustrates a blockdiagram of a GNSS receiver in the form of a general purpose GPS receiver1230 capable of demodulation of the L1 and/or L2 signal(s) received fromone or more GPS satellites. A more detailed discussion of the functionof a receiver such as GPS receiver 1230 can be found in U.S. Pat. No.5,621,416, by Gary R. Lennen, is titled “Optimized processing of signalsfor enhanced cross-correlation in a satellite positioning systemreceiver,” and includes a GPS receiver very similar to GPS receiver 1230of FIG. 12.

In FIG. 12, received L1 and L2 signals are generated by at least one GPSsatellite. Each GPS satellite generates different signal L1 and L2signals and they are processed by different digital channel processors1252 which operate in the same way as one another. FIG. 12 shows GPSsignals (L1=1575.42 MHz, L2=1227.60 MHz) entering GPS receiver 1230through a dual frequency antenna 1232. Antenna 1232 may be amagnetically mountable model commercially available from TrimbleNavigation of Sunnyvale, Calif. Master oscillator 1248 provides thereference oscillator which drives all other clocks in the system.Frequency synthesizer 1238 takes the output of master oscillator 1248and generates important clock and local oscillator frequencies usedthroughout the system. For example, in one embodiment frequencysynthesizer 1238 generates several timing signals such as a 1st (localoscillator) signal LO1 at 1400 MHz, a 2nd local oscillator signal LO2 at175 MHz, an SCLK (sampling clock) signal at 25 MHz, and a MSEC(millisecond) signal used by the system as a measurement of localreference time.

A filter/LNA (Low Noise Amplifier) 1234 performs filtering and low noiseamplification of both L1 and L2 signals. The noise figure of GPSreceiver 1230 is dictated by the performance of the filter/LNAcombination. The down convertor 1236 mixes both L1 and L2 signals infrequency down to approximately 175 MHz and outputs the analogue L1 andL2 signals into an IF (intermediate frequency) processor 1250. IFprocessor 1250 takes the analog L1 and L2 signals at approximately 175MHz and converts them into digitally sampled L1 and L2 inphase (L1 I andL2 I) and quadrature signals (L1 Q and L2 Q) at carrier frequencies 420KHz for L1 and at 2.6 MHz for L2 signals respectively.

At least one digital channel processor 1252 inputs the digitally sampledL1 and L2 inphase and quadrature signals. All digital channel processors1252 are typically are identical by design and typically operate onidentical input samples. Each digital channel processor 1252 is designedto digitally track the L1 and L2 signals produced by one satellite bytracking code and carrier signals and to from code and carrier phasemeasurements in conjunction with the GNSS microprocessor system 1254.One digital channel processor 1252 is capable of tracking one satellitein both L1 and L2 channels. Microprocessor system 1254 is a generalpurpose computing device (such as computer system 1000 of FIG. 10) whichfacilitates tracking and measurements processes, providing pseudorangeand carrier phase measurements for a determining position fix logic1258. In one embodiment, microprocessor system 1254 provides signals tocontrol the operation of one or more digital channel processors 1252.According to one embodiment, the GNSS microprocessor system 1254provides one or more of pseudorange information 1272, Doppler Shiftinformation 1274, and real Carrier Phase Information 1276 to thedetermining position fix logic 1258. One or more of pseudorangeinformation 1272, Doppler Shift information 1274, and real Carrier PhaseInformation 1276 can also be obtained from storage 1260. One or more ofthe signals 1272, 1274, 1276 can be conveyed to the cellular device'sprocessor, such as processor 109 (FIG. 1A) that is external to the GNSSchipset 170 (FIG. 1A). Determining position fix logic 1258 performs thehigher level function of combining measurements in such a way as toproduce position, velocity and time information for the differential andsurveying functions, for example, in the form of a position fix 1280.Storage 1260 is coupled with determining position fix logic 1258 andmicroprocessor system 1254. It is appreciated that storage 1260 maycomprise a volatile or non-volatile storage such as a RAM or ROM, orsome other computer readable memory device or media. In someembodiments, determining position fix logic 1258 performs one or more ofthe methods of position correction described herein.

In some embodiments, microprocessor 1254 and/or determining position fixlogic 1258 receive additional inputs for use in receiving correctionsinformation. According to one embodiment, an example of the correctionsinformation is WAAS corrections. According to one embodiment, examplesof corrections information are differential GPS corrections, RTKcorrections, signals used by the previously referenced Enge-Talbotmethod, and wide area augmentation system (WAAS) corrections amongothers.

Although FIG. 12 depicts a GNSS receiver 1130 with navigation signalsL1I, L1Q, L2I, L2Q, various embodiments are well suited differentcombinations of navigational signals. For example, according to oneembodiment, the GNSS receiver 1130 may only have an L1I navigationalsignal. According to one embodiment, the GNSS receiver 1130 may onlyhave L1I, L1Q and L2I.

Various embodiments are also well suited for future navigationalsignals. For example, various embodiments are well suited for thenavigational signal L2C that is not currently generally available.However, there are plans to make it available for non-militaryreceivers.

According to one embodiment, either or both of the accessing logic 110Band the processing logic 150 reside at either or both of the storage1260 and GNSS microprocessor system 1254.

According to one embodiment, the GNSS receiver 1230 is an example of aGNSS receiver 107 (see e.g., FIG. 1A and FIG. 1D). According to oneembodiment, the determining position fix logic 1258 is an example ofdetermining position fix logic 170B (FIG. 1B). According to oneembodiment, position fix 1280 is an example of a position fix 172B (FIG.1B).

Kalman Filtering

FIG. 13 depicts an example Kalman filtering process 1300, according tosome embodiments. It should be appreciated that Kalman filtering is wellknown. As such, FIG. 13 and the associated discussion are utilized onlyto provide a high-level general description. Variations in the describedprocedures will occur during specific implementations of Kalmanfiltering. The extended Kalman filter and the unscented Kalman filterrepresent some of the variations to the basic method. Such variationsare normal and expected. Generally speaking, Kalman filtering is a basictwo-step predictor/corrector modeling process that is commonly usedmodel dynamic systems. A dynamic system will often be described with aseries of mathematical models. Models describing satellites in a GlobalNavigation Satellite System (GNSS) are one example of a dynamic system.Because the position of any satellite and/or the positions of all thesatellites in a system constantly and dynamically change and thesatellites output a signal that can be measured by a GNSS receiver,Kalman filtering can be used in determining positions of the satellites.

A basic Kalman filter implemented using Kalman filtering process 1300typically has at least two major components 1310: states 1311 andcovariances 1312. States 1311 represent variables that are used todescribe a system being modeled, at a particular moment in time.Covariances 1312 are represented in a covariance matrix that describesuncertainty, or lack of confidence, of states 1311 with respect to eachother at that same moment in time. Kalman filtering process 1300 alsohandles noise, or unpredictable variability, in the model. There are twoprinciple types of noise, observation noise 1341 and process noise 1321.A Kalman filter may handle additional noise types, in some embodiments.Process noise 1321 describes noise of the states 1311 as a function oftime. Observation noise 1341 is noise that relates to the actualobservation(s) 1340 (e.g., observed measurements) that are used as aninput/update to Kalman filtering process1300.

A prediction phase 1320 is the first phase of Kalman filtering process1300. Prediction phase 1320 uses predictive models to propagate states1311 to the time of an actual observation(s) 1340. Prediction phase 1320also uses process noise 1321 and predictive models to propagate thecovariances 1312 to time of the actual observation(s) 1340 as well. Thepropagated states 1311 are used to make predicted observation(s) 1322for the time of actual observation(s) 1340.

A correction phase 1330 is the second phase in the Kalman filteringprocess 1300. During correction phase 1330, Kalman filtering process1300 uses the difference between the predicted observation(s) 1322 andthe actual observation(s) 1340 to create an observation measurementresidual 1331, which may commonly be called the “measurement residual.”Observation noise 1341 can be noise in actual observation(s) 1340 and/ornoise that occurs in the process of taking the actual observation(s)1340. A Kalman gain 1332 is calculated using both the covariances 1312and the observation noise 1341. The states 1311 are then updated usingthe Kalman Gain 1332 multiplied by the observation measurement residual1331. The covariances 1312 are also updated using a function related tothe Kalman gain 1332; for example, in one embodiment where Kalman gainis limited to a value between 0 and 1, this function may be 1 minus theKalman gain. This updating is sometimes referred to as the “covarianceupdate.” In some embodiments, if no actual observation 1340 isavailable, Kalman filtering process 1300 can simply skip correctionphase 1330 and update the states 1311 and covariances 1312 using onlythe information from prediction phase 1320, and then begin again. Usingthe new definitions of the states 1311 and covariances 1312, Kalmanfiltering process 1300 is ready to begin again and/or to be iterativelyaccomplished.

Computer Readable Storage Medium

Unless otherwise specified, any one or more of the embodiments describedherein can be implemented using non-transitory computer readable storagemedium and computer readable instructions which reside, for example, incomputer-readable storage medium of a computer system or like device.The non-transitory computer readable storage medium can be any kind ofphysical memory that instructions can be stored on. Examples of thenon-transitory computer readable storage medium include but are notlimited to a disk, a compact disk (CD), a digital versatile device(DVD), read only memory (ROM), flash, and so on. As described above,certain processes and operations of various embodiments of the presentinvention are realized, in one embodiment, as a series of computerreadable instructions (e.g., software program) that reside withinnon-transitory computer readable storage memory of a cellular device100, 200 (FIGS. 1A-2) and are executed by a hardware processor of thecellular device 100, 200. When executed, the instructions cause acomputer system to implement the functionality of various embodiments ofthe present invention. For example, the instructions can be executed bya central processing unit associated with the cellular device 100, 200.According to one embodiment, the non-transitory computer readablestorage medium is tangible.

Unless otherwise specified, one or more of the various embodimentsdescribed herein can be implemented as hardware, such as circuitry,firmware, or computer readable instructions that are stored onnon-transitory computer readable storage medium. The computer readableinstructions of the various embodiments described herein can be executedby a hardware processor, such as central processing unit, to cause thecellular device 100, 200 to implement the functionality of variousembodiments. For example, according to one embodiment, the SUPL client101 and the operations of the flowcharts 400-1100 depicted in FIGS. 4-11are implemented with computer readable instructions that are stored oncomputer readable storage medium, which can be tangible ornon-transitory or a combination thereof, and can be executed by ahardware processor 109 of a cellular device 100, 200.

II. Performing Data Collection Using a Mobile Data Collection PlatformNotation and Nomenclature

Reference will now be made in detail to various embodiments of thesubject matter, examples of which are illustrated in the accompanyingdrawings. While various embodiments are discussed herein, it will beunderstood that they are not intended to be limited to theseembodiments. On the contrary, the presented embodiments are intended tocover alternatives, modifications and equivalents, which may be includedwithin the spirit and scope the various embodiments as defined by theappended claims. Furthermore, in the following Description ofEmbodiments, numerous specific details are set forth in order to providea thorough understanding of embodiments of the present subject matter.However, embodiments may be practiced without these specific details. Inother instances, well known methods, procedures, components, andcircuits have not been described in detail as not to unnecessarilyobscure aspects of the described embodiments.

Unless specifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the description ofembodiments, discussions utilizing terms such as “collecting,”“capturing,” “obtaining,” “determining,” “storing,” “calculating,”“calibrating,” “receiving,” “designating,” “performing,” “displaying,”“positioning,” “accessing,” “transforming data,” “modifying data totransform the state of a computer system,” or the like, refer to theactions and processes of a computer system, data storage system, storagesystem controller, microcontroller, hardware processor, such as acentral processing unit (CPU), or similar electronic computing device orcombination of such electronic computing devices. The computer system orsimilar electronic computing device manipulates and transforms datarepresented as physical (electronic) quantities within the computersystem's/device's registers and memories into other data similarlyrepresented as physical quantities within the computer system's/device'smemories or registers or other such information storage, transmission,or display devices.

Overview of Discussion

According to one embodiment, a mobile data collection platform capturesan image that depicts at least one point of interest. The location andorientation of the mobile data collection platform may be captured atthe time the image is captured. The orientation of the mobile datacollection platform is with respect to a local gravity vector that islocal to the mobile data collection platform. The orientation, accordingto one embodiment, is given by a three axis tilt angle sensor and thedirection of the tilt angle may be determined from the tilt angles forthe x-axis sensor and the y axis sensor, as determined by aiming themeasurement platform towards the point of interest. The tilt sensormeasures degree of departure from local gravity vertical in 2 or 3 axes.The location and orientation can be associated with the image, forexample, by the user holding the mobile data collection platform stillduring the period of time that the image is captured and the locationand orientation of the mobile data collection platform are determined.In another example, when a user of the mobile data collection platformpresses a button, the image, the location and the orientation can all beobtained and stored in response to the user pressing the button.Therefore location and orientation can be associated with the image bydetermining the location and orientation and capturing the image in atime period that is short enough to avoid any significant user movementof the mobile data collection platform during the capture process.

Scale Information may be used as a part of determining a distancebetween the mobile data collection platform and the point of interest.The scale information may be the depiction of an object, which has aknown dimension, in the captured image. A single measurement can be madeif the plane of scale object is parallel to the plane of the imagecapture device. This is hard to achieve, so two images are usuallyrequired. In another example, a second image that depicts the point ofinterest captured with the image capturing device that is at a secondlocation and orientation where the first location and the secondlocation are separated by a known distance. Since the mobile datacollection platform has a position determination system, the distancebetween the first location and the second location can be easilydetermined, as will become more evident. In this case, scale informationcan include one or more of the first and second images, the first andsecond locations and orientations that were used when the respectivefirst and second images were captured, and the known distance betweenthe first and second locations.

Mobile Data Collection Platform A First Embodiment

FIG. 14 depicts a block diagram of a mobile data collection platform1400, according to one embodiment. Examples of a mobile data collectionplatform 1400 are a cell phone, a non-voice enabled cellular device, atablet computer, a phablet, and a mobile hand-held GNSS receiver. Themobile data collection platform 1400 may be used while moving orstationary, since it may be operated in a hand-held position or secured,for example, on a monopod or tripod or a mobile platform attached to avehicle. Examples of a tablet computer are the Microsoft Surface, AppleiPads, Apple iPad mini, iPad tablet, Nexus 7, Samsung Galaxy Tabfamilies, and the Samsung Galaxy Note. According to one embodiment, amobile data collection platform 1400 is a mobile communications device(MCD) with cellular communications capabilities (also referred to as a“cellular communication enabled mobile communications device”).

The mobile data collection platform 1400 includes a cellular device1410, processing logic 1480, an image capturing device 1430, anorientation system 1470, an inertial orientation system 1440, tiltsensor 1442, compass 1444, and hardware 1420. The cellular device 1410includes a display 1414, GNSS chipset 1413 and an antenna 1412. Thehardware 1420 includes the image capturing device 1430, the orientationsystem 1470, the inertial orientation system 1440, hardware memory 1450and hardware processor 1460. The antenna 1412, the display 1414, theprocessing logic 1480, the hardware 1420 are part of the mobile datacollection platform 1400 and outside of the GNSS chipset 1413.

According to one embodiment, the orientation system 1470 includes acompass 1444 and an inertial orientation system 1440. According to oneembodiment, the inertial orientation system 1440 includes a three-axistilt sensor 1442. According to one embodiment, the tilt sensor 1442 is athree-axis inertial measurement unit (IMU). According to one embodiment,the tilt sensor 1442 is a three-axis accelerometer. According to oneembodiment, the tilt sensor 1442 is a two-axis accelerometer where theaxes are for the x and y directions in the platform coordinate system.

The orientation system 1470, according to one embodiment, determinesorientation information 1456 that represents an orientation of themobile data collection platform 1400. The orientation information 1456includes, according to one embodiment, inertial orientation information1458 and azimuth angle. According to one embodiment, the inertialorientation information 1458 includes a tilt angle from the tilt sensor1442.

Angles, such as the azimuth angle, are measured in 360 degrees, as iswell known in the art. However, other metrics used by surveyors fordescribing angular displacement, including what is known as “grad” thatuses 400 degrees in a full circle can also be used.

The tilt sensor 1442 may be used to determine the tilt angle. The tiltangle indicates the mobile data collection platform 1400's orientationwith respect to a local gravity vector, as measured from a vertical orzenith point. The overall tilt angle is composed of two angles, tilt inthe direction of the x axis and tilt in the direction of the y axis. Thevector magnitude gives a tilt angle in the direction of the vector sumof the x-axis and y-axis components. It may be reported as a tilt anglein polar coordinates as well. Polar coordinates the tilt angle asmeasured from a vertical gravity reference direction along a compassangle, as determined by the vector sum of the x and y components. Tiltsensors 1442 determine the tilt angle based on Euler angles. Theinertial orientation information 1458 may include the Euler angles fromthe tilt sensor 1442 in addition to the tilt angle or instead of thetilt angle.

The compass 1444 may be used to determine the azimuth angle. The azimuthangle indicates the orientation, for example, with respect to areference direction, such as true north, magnetic north or a referencetarget at a known location, from which the direction vector can bedetermined.

The hardware memory 1450 stores the image 1452 that depicts the point ofinterest, the position fix 1454 and the orientation information 1456.The antenna 1412 has a three dimensional GNSS position fix Xpf, Ypf, Zpfthat is stored in memory as position fix 1454.

The hardware processor 1460 is for executing the capturing of the image1452 with the image capturing device 1430, where the image 1452 includesat least one point of interest, the determining of the position fix 1454of the mobile data collection platform 1400 based on the rawobservables, where the position fix 1454 provides a location of themobile data collection platform 1400 in a GNSS coordinate system, theaccessing of the orientation information 1456 from the inertialorientation system 1440, and the storing of the image 1452, the positionfix 1454 and the orientation information 1456 in the hardware memory1450 of the mobile data collection platform 1400.

The mobile data collection platform 1400 is not required to be leveledas a part of capturing the image 1452, determining the position fix1454, and determining the orientation information 1456. The orientationinformation 1456 is associated directly and automatically with a threedimensional location, such as the position fix Xpf, Ypf, Zpf (stored asposition fix 1454) or the three dimensional location X0, Y0, Z0 of anentrance pupil center, of the mobile data collection platform 1400 whenthe image 1452 was captured. The mobile data collection platform 1400 isnot required to be leveled at the time that the position fix Xpf, Zpf,Ypf and the orientation information 1456 are determined as is commonwith other optical measurement devices such as theodolites or totalstations.

Any one or more of the entities, such as hardware 1420, image capturingdevice 1430, inertial orientation system 1440, compass 1444, hardwarememory 1450, hardware processor 1460, that are part of the mobile datacollection platform 1400, 1500 and outside of the cellular device 1410can instead be inside of the cellular device 1410. According to oneembodiment, the mobile data collection platform 1400, 1500 is a cellulardevice. For example, a tablet computer may contain all the recitedhardware, plus a separate cellphone module, which itself can containsome of the hardware items, including a GNSS chipset. Conversely, thetablet may contain a GNSS chipset whose raw observables may be madeavailable to any of the processors associated with the tablet.

Various types of information can be stored, for example, in an EXIF fileassociated with the image 1452. Examples of information that can bewritten into the EXIF file are the GPS position fix 1454, orientationinformation 1456, the tilt angle, the direction of an azimuth angle(also referred to as an “azimuth direction” or “tilt direction”), scaleinformation, and antenna-to-entrance-pupil-center-geometric-information.Any type of information that can be used for determining one or more ofa three dimensional position of the entrance pupil center of the imagecapturing device, a distance from the entrance pupil center to a pointof interest and a location of a point of interest, as will become moreevident, can be stored in the EXIF file. Alternatively, any or more ofthe same information can be stored as reference information in asuitable reference file associated with the particular mobile datacollection platform.

Mobile Data Collection Platform A Second Embodiment

FIG. 15 depicts another block diagram of a mobile data collectionplatform 1500, according to one embodiment. According to one embodiment,the mobile data collection platform 1500 includes the blocks that are inmobile data collection platform 1400. In addition, mobile datacollection platform 1500 includes processing logic 1570, cellularcommunications 1510 and Bluetooth communications 1520. According to oneembodiment, the processing logic 1800, blue tooth communications 1520,cellular communications 1510 and hardware 1420 are a part of the mobiledata collection platform 1500 and outside of the GNSS chipset 1413.

Relationships Between Entities of FIG. 14 and FIG. 15 and Entities inPrevious Figures

The mobile data collection platforms 1400 and 1500 depicted in FIG. 14and FIG. 15 include a cellular device 1410. According to one embodiment,the cellular device 1410 can include cellular devices, such as cellulardevice 100, 200, or any other cellular device described herein or anycommunications system capable of connecting with a cellular telephonesystem, private or public, for the purpose of transmitting and receivingvoice, data, and messaging information.

An example of an image capturing device 1430 is a digital camera orportion thereof, which includes an electronic image sensor (e.g., acharge coupled device (CCD) image sensor, an Active Pixel Sensor (APS)image sensor, or other form of electronic image sensor). An example ofhardware memory 1450 is memory 210. An example of hardware processor1460 is hardware processor 109. An example of a GNSS chipset 1413 isGNSS chipset 170. According to one embodiment, the mobile datacollection platform 1400 includes a SUPL client, as described herein.The SUPL client can be inside of the cellular device 1410 or can be inthe mobile data collection platform 1400 and outside of the cellulardevice 1410.

According to various embodiments, the mobile data collection platform1400, 1500 can include any one or more of features described herein. Forexample, the mobile data collection platform 1400, 1500 can include atleast any one or more features depicted in FIGS. 1A-2, 12, and 13, andcan perform at least any one or more operations as depicted in FIGS.3-11, 20-33.

Processing Logic

Both mobile data collection platforms 1400 and 1500 include processinglogic.

FIG. 16 depicts a block diagram of processing logic 1480 for mobile datacollection platform 1400, according to one embodiment.

For example, the processing logic 1480 includesorientation-information-determination-logic 1610,inertial-orientation-information-determination-logic 1620,store-location-of-point-of-interest-determination-information-logic1630, and a true north declination angle application 1640.

Orientation information can include one or more of tilt angle andazimuth angle. Orientation-information-determination-logic 1610 includesthe inertial-orientation-information-determination-logic 1620, accordingto one embodiment. However, 1610 and 1620 can be separate. For example,instructions for 1610 and 1620 may be part of the same procedure orfunction or may be part of separate procedures or functions.

The inertial-orientation-information-determination-logic 1620 thatreceives Euler angles from the inertial orientation system 1440 andprocesses the Euler angles to provide the tilt angle of the mobile datacollection platform. The Euler angles may be stored in hardware memory1450.

The orientation-information-determination-logic 1610 receivesinformation from the compass 1444 and determines the tilt direction,according to one embodiment.

The orientation information 1456, according to one embodiment, includesinformation that provides a three dimensional position of the mobiledata collection platform 1400. The orientation information 1456 and theposition fix 1454 can be used for determining the three dimensionalposition X0, Y0, Z0 (FIG. 24) of and/or associated with the mobile datacollection platform 1400 in a local three dimensional coordinate system.

Since the inertial orientation system 1440 provides informationpertaining to the tilt angle of the mobile data collection platform1400, the mobile data collection platform 1400 is not required to beleveled as a part of obtaining thelocation-of-point-of-interest-determination-information.

The store-location-of-point-of-interest-determination-information-logic1630, according to one embodiment, can storelocation-of-point-of-interest-determination-information, such as theposition fix 1454, the image 1452 and the orientation information 1456,into the hardware memory 1450 of the mobile data collection platform.

For example, in an embodiment, a mobile data collection platform 1400,1500 captures an image 1452 that depicts a point of interest for thepurpose of determining a distance between a three dimensional positionof the mobile data collection platform 1400, 1500, such as the threedimensional position of the entrance pupil center, and the point ofinterest. The mobile data collection platform 1400, 1500 collectsvarious types of information that can be used for calculating thedistance between the point of interest and the three dimensionalposition of the data collection platform 1400, 1500. The collectedinformation that can be used for determining the distance shall bereferred to as“location-of-point-of-interest-determination-information.”

According to one embodiment, thelocation-of-point-of-interest-determination-information includes morethan one image 1452. Thelocation-of-point-of-interest-determination-information can include anytype of information that can be used for determining the location of thepoint of interest, according to one embodiment. Thelocation-of-point-of-interest-determination-information may include anytype of information that can be used for determining the location of thepoint of interest in a three dimensional coordinate system, according toone embodiment. According to one embodiment, the three dimensionalcoordinate system that the point of interest can be located in is thewell-known latitude, longitude and altitude, or height, system used inmapping. The GNSS receiver first locates itself in the WGS-84 WorldGeodetic System standard coordinate system widely accepted for use incartography, geodesy, and navigation and used to describe the shape andcoordinates of the earth. The WGS-84 datum includes the definition of areference ellipsoid, which approximates the earth's geoid. The WGS-84datum is used for referencing GNSS-derived positions to the earth.Models are available for relating WGS-84 derived heights to mean-sealevel (geoid) heights, such as the Earth Gravitational Model 1996.According to one embodiment, WGS-84 coordinate system includes WGS-84datum. A conversion system within the GNSS receiver converts theGNSS-determined WGS-84 data into latitude, longitude and altitudeinformation which are then used in the local coordinate system. Data onpoints of interest will be measured and transformed into the same localcoordinate system. According to one embodiment, the information includesany type of information that can be used for determining the location ofthe point of interest in a three dimensional coordinate system so thatthe mobile data collection platform 1400 is not required to be leveledas a part of determining the location of the point of interest.

According to one embodiment, a true north declination angle application1640 provides a declination angle for true north from the latitude andlongitude associated with a position fix, such as the position fix Xpf,Ypf, Zpf of an antenna 1412. For example, according to one embodiment,the orientation of the mobile data collection platform 1400, 1500 at thetime the image depicting the point of interest includes a tilt directionthat is determined with respect to a reference direction. According toone embodiment, the reference direction is true north.

Compasses provide the direction to magnetic north. True north can bedetermined by applying compensations to the direction of magnetic northprovided by a compass.

One of the functions of the true north declination angle application1640 that is used according to various embodiments, is obtainingcompensations that can be applied to the direction of magnetic northprovided by a compass to obtain true north. For example, the true northdeclination angle application 1640 can communicate with a databaseprovided by the U.S. government that provides the declination angle fortrue north from the latitude and longitude associated with a positionfix, such as the position fix Xpf, Ypf, Zpf of an antenna 1412.Therefore, according to various embodiments, the true north declinationangle application 1640 can provide the position fix Xpf, Ypf, Zpf of thecurrent location of the antenna 1412 to the U.S. governments database.The U.S. government's database can use the position fix Xpf, Ypf, Zpf tolocate compensations, such as declination angle for true north, from thelatitude and longitude associated with a position fix Xpf, Ypf, Zpf andreturn the compensations to the true north declination angle application1640. Magnetic north, while the platform 1400 is at the same positionXpf, Ypf, Zpf, can be obtained from the compass 1444. True north can bederived, for example, by applying the compensations to the magneticnorth.

The processing logic 1480, according to one embodiment, providesinstructions for communicating the position fix Xpf, Ypf, Zpf to thetrue north declination angle application 1640 and requestingcompensations that correlate with the position fix Xpf, Ypf, Zpf,receiving the compensations, receiving magnetic north from the compass1444, and determining true north by applying the compensations tomagnetic north.

FIG. 17 depicts processing logic 1570 for mobile data collectionplatform 1500, according to one embodiment. According to one embodiment,the processing logic 1570 is a part of the mobile data collectionplatform 1400, 1500 and outside of the GNSS chipset 1413.

Data Collection Utilities Processing Logic 1570, according to oneembodiment, includes image outliner 1772, feature identification 1774,pattern recognition 1776, and image editor 1778. The processing logic1570 may include processing logic 1480.

According to one embodiment, a captured image 1452 can be displayed onthe display 1414. The user of the mobile data collection platform 1400can outline a point of interest that is represented in image 1452depicted on display 1414. The user can specify that a point or featureis a point of interest, for example, by outlining it. The image outliner1772 can receive information indicating the outline that the user drewaround the point of interest. Therefore, a point of interest that hasbeen outlined is an example of a “user specified point of interest.” Aswill become more evident, a user can also specify a point of interestusing crosshairs shown in the display, and aligned with the major axisof the image capturing device 1430's lens (also known as an “entrancepupil”). Feature identification can be performed, for example, byfeature identification 1774 on a user specified point of interest.Pattern recognition 1776 can be performed on a user specified point ofinterest.

The user can use the image editor 1778 to annotate the image 1452 forexample with audio or text or a combination thereof. The annotation canbe a description of a point of interest. For example, the user canindicate in the annotation that the point of interest is a standardsurvey target device consisting of concentric circles with alternatingblack and white sections, or the upper right corner of a door or otherpoint of interest or pseudo point of interest, as described herein.These are just a couple of examples of annotations. Therefore, a pointof interest that a user specifies using an annotation is another exampleof a user specified point of interest. The annotation can include otherinformation such as a description of the area or a job site where theimage 1452 was taken.

For more information on cellular communications 1510, Bluetoothcommunications 1520, image outliner 1772, feature identification 1774,pattern recognition 1776 and image editor 1778 refer to U.S.2012/0163656 filed on Jun. 28, 2012 entitled “Method/Apparatus forimage-based positioning” by Soubra et al, having Attorney Docket No.TRMB-A2194, and assigned to the assignee of the present application.Refer also to the contents of U.S. 2012/0330601 filed on Feb. 15, 2012entitled “Determining Tilt Angle and Tilt Direction Using ImageProcessing” by Soubra et al, and assigned to the assignee of the presentapplication.

FIG. 18 depicts processing logic, according to one embodiment. Theprocessing logic 1800 can be included in either processing logic 1480 or1570 of a mobile data collection platform 1400, 1500. According to oneembodiment, the processing logic 1800 is part of the mobile datacollection platform 1400, 1500 and outside of the GNSS chipset 1413.

Referring to FIG. 18, the processing logic 1800 includes crosshairsprocessing logic 1810, bubble level processing logic 1820, and distancebetween two positions logic 1840. The processing logic 1800 may includeprocessing logic 1480 or processing logic 1570 or a combination thereof.

The crosshairs processing logic 1810 receives and processes informationwith respect to a crosshair display overlay, as will become moreevident.

The bubble level processing logic 1820 can receive information from thetilt sensor 1442 and use the received information to display a graphicalvisual representation of a bubble inside of the electronic bubble leveloverlay, as will become more evident.

According to one embodiment, the distance between two positionsprocessing logic 1840 obtains the position fixes associated with twolocations that a mobile data collection platform took images of a pointof interest and determines a distance between the two locations based onthe position fixes.

According to one embodiment, one or more of the processing logics 1480,1570, 1800 are executed by one or more hardware processors 1460 that arepart of the mobile data collection platform 1400 and outside of the GNSSchipset 1413.

FIG. 19 depicts a mobile data collection platform 1400 orientedaccording to one embodiment. The mobile data collection platform 1400includes an entrance pupil 1942 (of its image capture device1430) and anaxis 1943 that is at the center 1902 of the entrance pupil 1942. Threeaxes x, y and z are depicted in FIG. 19. The x axis runs approximatelyparallel to the ground and parallel to the longer side of mobile datacollection platform 1400. The y axis runs approximately parallel to theground and parallel to the shorter side of mobile data collectionplatform 1400. The z axis is vertical to the ground and parallel to thegravity vector, which represents the pull of gravity toward the earth'ssurface and is widely used in coordinate measurement systems to provideat least one degree of orientation for devices.

Due to the orientation of mobile data collection platform 1400, theimage plane 1950 that defines the orientation of an image captured withthe image capturing device 1430 of mobile data collection platform 1400would be defined by the x axis and z axis and the ground plane 1960 thatis approximately parallel to the ground would be defined by the x axisand the y axis.

The body of mobile data collection platform 1400 is often tipped so thatit is no longer in a vertical orientation. In this case, the imagecapture device 1430 may view the nearby ground as well as objects in theforeground. No loss of functionality of position shift motion detectionoccurs for the LMM system.

Photogrammetry is the practice of determining the geometric propertiesof objects from photographic images. In the simplest example, thedistance between two points that lie on a plane parallel to thephotographic image plane can be determined by measuring their distanceon the image, if the scale s of the image is known. This is done bymultiplying the measured distance by a scale factor 1/S.

One way of finding points uses features to identify the desired object,or point on a desired object. An example of an object is a door and anexample of points on the object are the corners of the door. The pointsmay be described by a “feature description” of the object. For example,the door's corners may be represented by a small collection of closelyassociated details, or image ‘bits’ which form a distinct andrecognizable image pattern. Modern image processing methods areavailable for identifying such grouping of image bits as “featurepoints.”

Calibrating the Mobile Data Collection Platform

According to one embodiment, there are two types of calibration thatenable satisfactory operation of an image capturing device 1430 withphotogrammetric analyses. The first type of calibration is adetermination of the angular displacement associated with each pixel, orcharge coupled device capture element. This may be done mathematically,for example, by determining the entire field of view of the imagecapturing device using external means, and then dividing this angularfield of view by the number of pixel elements in each dimension,horizontally and vertically. This external mathematical means is wellknown in the art and includes measuring a distance from a referenceplane, such as a wall, to the entrance pupil of the image capturingdevice, and then marking the edges of the field of view, horizontallyand vertically, for example, on the image plane (also known as a“reference plane”). The distance from each edge, horizontally andvertically, plus the distance from the entrance pupil to the imageplane, enable creation of a triangle whose angles for horizontal andvertical, can be determined, thus, defining the field of view inhorizontal and vertical planes relative to the image plane. An exampleof an image plane is illustrated in FIG. 19.

The second type of calibration deals with lens aberrations. Imagecapturing devices that are a part of cellular devices (also referred toas “internal image capturing devices”) typically have poor qualitylenses where the image is distorted by a variety of lens aberrations, sothat what is a uniform distance metric in an image, such as acheckerboard square pattern, becomes less uniform, particular near theedges of the field of view. Therefore, according to one embodiment, theimage capturing device, namely the camera and its lens, must becalibrated.

Calibration can be done for a family of lenses associated with aparticular image capturing device, or may be done on an individual basisfor each mobile data collection platform. The purpose of calibration isto 1) limit the useful area of the captured image data to only thosepixels on the charge-coupled device (CCD) that have a satisfactorilyuniform image transform from the real world to the image capturingdevice's collection of CCD pixels, or 2) to define the variation oftransform information for the entire field of view in order to create acorrection map for segments of pixels where distortion is greatest,namely at the periphery of the field of view.

FIG. 20 depicts a pattern 2010 that can be used for calibrating a mobiledata collection platform, according to one embodiment. According to oneembodiment, the pattern 2010 is a pattern of features. The features mayeach have the same shape or size, or a combination thereof. As depictedin FIG. 20, the pattern 2010 is formed by a checker board square whereeach checker is a square. As depicted in FIG. 20, there are enoughfeatures (e.g., checkerboard squares) to fill the image capturingdevice's entire field of view (FOV) 2030.

As stated, poor quality lenses cause aberrations and/or distortions. Forexample, if an image of the pattern 2010 is captured using a poorquality lens, the features, such as the checkers in FIG. 20, depicted inthe image will not have the same proportions as the pattern 2010. Thedistortion tends to increase toward the peripheries of the lens (alsoknown as “stretch distortion”). The kind and range of distortions inlenses are well-known in the image processing arts. For example, towardthe center of the captured image, the dimensions of the checkers willtend to be 1.00 by 1.00. However, the dimensions of the checkers willincreasingly be distorted the further the checkers are from the center.For example, the checker 2070 at the center may have a height of 1.00and a width of 1.00 and then as moved out the checker 2072 may have aheight of 1.00 and a width of 1.05 and then as move still further towardthe periphery the checker 2074 may have a height of 1.00 by width of1.06. The pixel correction datum 2050 is a correction map for segmentsof pixels where distortion is greatest, namely at the periphery of thefield of view 2030, according to one embodiment. The pixel correctiondatum 2050 can be stored in the hardware memory 1450.

There are other types of distortion effects besides a linear stretching,such as pin cushion and barrel distortions, for which alternatespecifications for a distortion limit are available, as is well known inthe art.

FIG. 21 depicts a calibration image 2160 that is an image that the imagecapturing device 1430 took of the pattern 2010 depicted in FIG. 20,according to one embodiment. The calibration image 2160 has anunacceptable level of distortion between the boundary 2180 of theacceptable region 2140 and the periphery 2185.

According to one embodiment, a quality threshold metric is used todetermine the acceptable region 2140, within the boundary 2180, wherethe distortion is within an acceptable level. For example, if thecalibration image 2160 displaying the width of the squares as movetoward the periphery do not differ by more than 5 percent from the widthof a square closest to the pointing vector PV, then the pixels for thatsquare are included in the acceptable region 2140. According to anotherembodiment, if the width of the squares nearing the periphery 2185 donot differ by more than 2 percent from the width of the square 2070closet to the pointing vector PV (FIG. 20), then the pixels for thatsquare 2070 are included in the acceptable region 2140. Thus, a boundary2180 can be determined for the CCD image capturing device such thatimage data in the acceptable region 2140 inside the boundary 2180 isused for photogrammetry analysis purposes, and unacceptable region 2190between the boundary 2180 and the periphery 2185 is ignored.

According to one embodiment, calibrations are not performed for everysingle mobile data collection platform that is manufactured. Accordingto one embodiment, calibrations are performed for each type of mobiledata collection platform. For example, if there are two types of mobiledata collection platforms that are manufactured and there are 1000mobile data collection platforms for each of the two types, twocalibrations are performed instead of 2000. According to one embodiment,calibrations are performed for each type of lens or are performed foreach type of image capturing device.

A mobile data collection platform can be calibrated, for example, beforeit is purchased or after it is purchased. The mobile data collectionplatform can be calibrated, for example, at the manufacturing facilityor by a user who bought the mobile data collection platform.

GNSS Raw Observables

A mobile data collection platform 1400, 1500 accesses an internal GNSSchipset 1413, extracts raw observables from the internal GNSS chipset1413 and determines a position fix Xpf, Ypf, Zpf based on the extractedraw observables, according to various embodiments described herein. Theextracted raw observables can include raw pseudoranges. Although variousembodiments are described in the context of a “GPS position fix,” sincevarious position fixes are determined based on GNSS raw observables, theterm “GNSS” shall be understood as including “GPS.”

“Raw observables” shall be used to refer to the specific data comprisingraw observables that are extracted from the internal GNSS chipset. Theraw observables can include real carrier phase information or DopplerShift Information. The raw pseudoranges may be smoothed based on realcarrier phase information or reconstructed carrier phase information,according to various embodiments described herein. The pseudoranges maybe corrected, for example, based on external corrections obtained fromcorrection sources that are external to a mobile data collectionplatform, as described herein. A position fix may be smoothed based onlocally measured movement information, as described herein. Thepseudoranges that are used for determining a position fix of the mobiledata collection platform may be uncorrected unsmoothed pseudoranges,corrected unsmoothed pseudoranges, uncorrected smoothed pseudoranges, orcorrected smoothed pseudoranges, as described herein. The position fixesmay or may not be smoothed based on locally measured movementinformation, as described herein.

Point of Interest Real or Pseudo

A data collection platform 1400, 1500 captures an image 1452 thatdepicts a point of interest for the purpose of determining a distancebetween a three dimensional position of the data collection platform1400, 1500, such as the three dimensional position of the entrance pupilcenter, and the point of interest, by photogrammetric methods. Otherdimensions between other points in the image may also be determined.

According to one embodiment, a point of interest is stationary.According to one embodiment, a point of interest has a three dimensionalcoordinate. Examples of a point of interest are corners, in an outdoorsetting or indoor setting, wall-mounted fixture of various kinds, suchas lights, switches, window ledges, window corners, in an indoorsetting, a property boundary point, a point of significance to a currentor proposed construction project, and/or the like. A point of interestis also commonly referred to as “target point,” or “object point.” Apoint of interest may be any point on an object that is of interest. Itmay be a topographic feature, a manmade structure, or component thereof,such as a corner of a building, the edge of a wall, the point at whicheither of these contacts the ground. A single pixel or a group of pixelsin an image 1452 can represent or be a point of interest.

Points of interest on moving objects may also be captured by the mobiledata collection platform. With the mobile data collection platform, timeof data capture, location of the platform, and an image of the movingobject can be obtained. Such mobile points of interest may includefeatures on a vehicle including but not limited to door handles, wheels,logos, emblems, windows, edges, or corners.

According to one embodiment, the pointing vector represents a line thatpoints from the entrance pupil center to the point of interest. However,embodiments are also well suited for using a point of interest that thepointing vector was not pointing directly at as long as the point ofinterest is in the image 1452. For example, if the pointing vector isnot pointing at the real point of interest, then the point that thepointing vector is pointing at can be used as a “pseudo point ofinterest.” The real point of interest that is also depicted in the imagecan be identified, for example, in relation to the pseudo point ofinterest. The pseudo point of interest can be represented by a singlepixel or a group of pixels in an image 1452 where the single pixel orthe group of pixels represents anything in the field of view capturedwith the image 1452. For example, a pseudo point of interest can be anytype of point or feature that a point of interest can be. Further, thepseudo point of interest may represent something that is not a realpoint of interest. For example, the pseudo point of interest may beanywhere on a wall where there are no corners, windows or doors, orother features.

Photogrammetric techniques that are well known in the art can be used todetermine the three dimensional location of the real point of interest,for example, based on the three dimensional relationship between thereal point of interest and the pseudo point of interest, and angles andscale factors determined during a data capture event.

A real point of interest and/or a pseudo point of interest can beselected after or before the image 1452 has been captured.

Orientation Information

A mobile data collection platform 1400, 1500 has an orientation when animage capturing device 1430 captures an image 1452 that depicts a pointof interest. The orientation of the mobile data collection platform1400, 1500 when the image 1452 is captured is stored as orientationinformation 1456. Examples of orientation information 1456 includes oneor more of tilt angle and tilt direction, as determined by the azimuthangle given by the internal compass 1444. Inertial orientationinformation 1458 includes tilt angle.

The tilt angle refers to an angle between a real world vertical axis(e.g., local gravity vector) and a vertical axis of the mobile datacollection platform. The tilt direction refers to orientation, typicallyrelative to the local vertical axis, in the x and y directions, or maybe represented in a polar coordinate system Azimuth angle (or referredto as just “azimuth”) refers to an angle between a reference directionand a line from the user of the mobile data collection platform to thepoint of interest, as projected on the same plane as the referencedirection, typically a horizontal plane. Examples of a referencedirection are true north, magnetic north or a reference target at aknown location, from which the direction vector can be determined, forexample.

FIG. 22 depicts a three dimensional view of relationships between thelocal coordinate system, the platform coordinate system of a mobile datacapturing device, and a pointing vector of an image capturing device1430, according to one embodiment.

FIG. 22 depicts the local coordinate system that is represented by Xlocal axis 2203, Y local axis 2201 and Z local axis 2202, the platformcoordinate system that is represented by x platform axis 2240, yplatform axis 2220, z platform axis 2230, the three dimensionalcoordinates X0, Y0, Z0 of the entrance pupil center, a point of interest2250, a horizontal plane HP, the pointing vector PV, the horizontal lineHL, an azimuth angle AZ, an elevation angle EL, and a tilt angle T 2204.

The local coordinate system includes the X local axis 2203, whichrepresents east, the Y local axis 2201, which represents north, and theZ local axis 2202, which represents the local gravity vector 2270.

The platform coordinate system of the mobile data collection platform1400 includes the x platform axis 2240, the y platform axis 2220, andthe z platform axis 2230. According to one embodiment, the y platformaxis 2220 is parallel with the MDCP 1400's length, the z platform axis2230 is parallel with the MDCP 1400's depth and the x platform axis 2240is parallel with the MDCP 1400's width.

One end of the pointing vector PV is located at the entrance pupilcenter X0, Y0, Z0 of the image capturing device 1430 and the other endof the pointing vector PV is located at the point of interest 2250 or apseudo point of interest. The pointing vector PV lies along the centerline of the axis of the lens and its pupil.

The horizontal plane HP is about the three dimensional coordinates X0,Y0, Z0 of the entrance pupil's center. The horizontal line HL is in thehorizontal plane HP. One end of the horizontal line HL is located at theentrance pupil center's coordinates X0, Y0, Z0. The horizontal line HLis directly below the pointing vector PV so that the horizontal line HLand the pointing vector PV are in the same vertical plane.

The tilt angle T 2204 is between the Z local axis 2202 and the yplatform axis 2220. The azimuth angle AZ is between the Y local axis2201 (north) and the horizontal line HL. The elevation angle EL isbetween the horizontal line HL and the pointing vector PV. According toone embodiment, the tilt angle T 2204 and the elevation angle EL measurehave the same measurement, by congruent triangles. Therefore, themeasurement of the tilt angle T 2204 can be used as the measurement ofthe elevation angle EL.

Point 2922 is located in the horizontal line HL and is directly belowthe point of interest 2250. There is a distance 2260 between the pointof interest 2250 and the point 2922. The line that represents thedistance 2260 is parallel with the local gravity vector 2270.

The pointing vector PV is in the negative direction of the z platformaxis 2230. The x platform axis 2240 and the y platform axis 2220 arehorizontal and vertical measurements of the image view. For example, they platform axis 2220 is the vertical dimension of an image 1452 and thex platform axis 2240 is the horizontal dimension of the image 1452.

FIG. 23 depicts a three dimensional view of a mobile data collectionplatform (MDCP) that is being used to perform data collection, accordingto one embodiment.

FIG. 23 depicts a mobile data collection platform 1400 taking a pictureof a house in a field of view 2310. The house appears on the MDCP 1400'sdisplay 1414. The antenna 1412, according to one embodiment, is insidethe MDCP 1400's casing (also referred to as “an internal antenna”). Acasing may also be referred to as a housing. An antenna 1412 may be abent wire that is inside the MDCP 1400's casing and is a proprietaryelement of the vendor of the mobile data collection platform 1400.

According to one embodiment, the mobile data collection platform 1400 isor includes a tilt sensor that is 2 or 3-axis accelerometer. Typicallymodern smart phones and tablets include a 2 or 3-axis accelerometer.Therefore, the mobile data collection platform is sensing the earth'sgravity vector, and as a result can automatically perform the samefunction that is manually performed for a typical optical total stationthat is known as “leveling.” Therefore, a mobile data collectionplatform can determine the tilt angle T 2204 as measured from a localgravity vector 2270, which is vertical, for any orientation of themobile data collection platform 1400.

The body of a mobile data collection platform 1400 and its principalaxes 2220, 2230, 2240 are not the same axes that are represented in thelocal coordinates. As discussed herein, the local gravity vector 2270 isused as the Z local axis 2202, true north is used as the Y local axis2201, and east is used as the X local axis 2203, as depicted in FIG. 23.The axes of the platform coordinate system are the x platform axis 2240,the z platform axis 2230 and the y platform axis 2220, as depicted inFIG. 23, and are the principal axes of the body of the mobile datacollection platform 1400.

According to one embodiment, when a user points their mobile datacollection platform 1400 at a point of interest 2250, the mobile datacollection platform 1400 has a vector direction along the optical axisof the image capturing device 1430, which may be referred to as one ofthe principal axes of the mobile data collection platform 1400. Hereinit is referred to as the pointing vector PV, but may also be referred toas a “negative z platform axis 2230.” In this case, the image displayedon the display 1414 represents an x and y pair of platform axes 2220,2240. According to the right hand rule, x platform axis 2240 mayrepresent the horizontal directions, y platform axis 2220 may representvertical directions, which are parallel to the local gravity vector 2270or the Z vector 2202 of the local coordinate system. Therefore, zplatform axis 2230 may represent negative direction towards the point ofinterest 2250 and the positive z platform axis 2230 direction in theplatform coordinate system is toward the user of the mobile datacollection platform 1400, not toward the point of interest 2250.

Because of the capability of a tilt sensor that is 2 or 3-axisaccelerometer, the orientation of the mobile data collection platform1400 relative to the local gravity vector 2270 in the local coordinatesystem is always available. The tilt angle T 2204 as measured from thelocal gravity vector 2270 to the z platform axis 2230 (also known as thevector direction along the optical axis) is independent of theorientation of the mobile data collection platform 1400 about theoptical axis depicted as pointing vector PV in FIG. 23. Therefore, anyrotation of the mobile data collection platform 1400 about the opticalaxis PV does not affect the tilt angle 2204. The tilt angle T 2204 maybe displayed on the display 1414. The tilt angle 2204 may be extractedfrom the tilt sensor 1442, for example, using an API from a suite ofAPI's that the tilt sensor 1442 provides.

Due to the independence between the tilt angle T 2204 and theorientation of the mobile data collection platform 1400 about theoptical axis PV, the handheld operation of the mobile data collectionplatform 1400 is foolproof with respect to measuring a vertical tiltangle T 2204 towards a point of interest, as centered by appropriatemanipulation of the mobile data collection platform 1400 towards thepoint of interest 2250. The mobile data collection platform 1400 may berotated about the optical axis PV and the determination of the tiltangle T 2204 determination and resulting determination of the elevationangle EL will always be the same, for example, as long as thephotographic image 2740 of the point of interest 2250 is visible withinthe crosshair display overlay 2721, as depicted in FIG. 27. Therefore,handheld operation of the mobile data collection platform 1400 isgreatly simplified and no tripod or monopod is required.

According to one embodiment, there are no intermediate operationsrequired to determine the tilt angle 2204. If the point of interest 2250is in the center 2750 of the crosshairs display overlay 2721, then thetilt angle 2204 with respect to the point of interest 2250 is defined.If the point of interest 2250 is not in the center 2750 of thecrosshairs display overlay 2721 (also referred to as “misalignment ofthe point of interest with respect to the crosshairs center”), themisalignment can be compensated for based on the number of pixels in theimage from a pixel in the image that is represented by the center 2750to a location of a pixel that represents the point of interest 2250 inthe image and applying the angular correction appropriate for eachpixels angular displacement.

Because the tilt angle T 2204 that is obtained from the tilt sensor 1442is measured with respect to the local gravity vector 2270, by congruenttriangles, this tilt angle T 2204 is exactly the same as the elevationangle EL that is used for polar coordinate operations to convert themobile data collection platform's data into the local coordinates.

Spatial Relationships with Respect to a Mobile Data Collection Platform

The position fix of a mobile data collection platform 1400 is determinedat the location of the antenna 1412. However, the position of an imageis defined to be at the entrance pupil of the mobile data collectionplatform. The local gravity vector and the tilt angle are determinedusing the orientation system 1470. Information relating the geometricrelationship between the entrance pupil and the antenna (also referredto as “antenna-to-entrance-pupil-center-geometric-information” or “knownspatial relationship”) can be used, according to various embodiments.

FIG. 24 depicts a side view of a mobile data collection platform,according to one embodiment. The mobile data collection platform 1400that includes an antenna 1412 and an entrance pupil with an entrancepupil center 1902. FIG. 24 also depicts the local gravity vector 2270,the pointing vector PV, the horizontal line HL, the three dimensionalposition Xpf, Ypf, Zpf, the three dimensional position X0, Y0, Z0, thetilt angle 2204, the elevation angle El, the y platform axis 2220, andthe z platform axis 2230.

The y platform axis 2220 is oriented along the length of the mobile datacollection platform 1400 and the z platform axis 2230 is oriented alongthe depth of the mobile data collection platform 1400. The horizontalline HL is horizontal with ground level and the entrance pupil center1902 is one end of the horizontal line HL.

The pointing vector PV is from the entrance pupil center 1902 to thepoint of interest 2250 and the distance 2450 is between the entrancepupil center 1902 and the point of interest 2250. The pointing vector PVis perpendicular to the front face of the mobile data capturing platform1400. For example, the pointing vector PV is at a right angle with boththe y platform axis 2220 and the x platform axis 2240.

The line 2270 is an imaginary line that represents the local gravityvector 2270. The tilt angle 2204 and the tilt direction are used toplace the imaginary line that represents the local gravity vector 2270through the center 1902 of the entrance pupil. The imaginary line thatrepresents the local gravity vector 2270 could be drawn other placesbesides through the entrance pupil center 1902 based on the tilt angle2204 and tilt direction.

The elevation angle El is the angle between the horizontal line HL andthe pointing vector PV. The tilt angle 2204 is the angle between thelocal gravity vector 2270 and the y platform axis 2220.

FIG. 24 depicts a y axis offset 2406 between the antenna 1412 and theentrance pupil center 1902. The GPS position fix coordinates Xpf, Ypf,Zpf are the three dimensional position of the antenna 1412 in the GNSScoordinate system. The coordinates X0, Y0, Z0 represent the threedimensional position of the entrance pupil center 1902 in the localcoordinate system.

FIG. 25 depicts a top view of a mobile data collection platform (MDCP)1400, according to one embodiment. FIG. 25 depicts the antenna 1412, theentrance pupil center 1902, the x axis offset 2501 between the antenna1412 and the entrance pupil center 1902 and the z axis offset 2502between the antenna 1412 and the entrance pupil center 1902. FIG. 25also depicts the x platform axis 2240 and the z platform axis 2230.According to one embodiment, the x platform axis 2240 is the width ofthe MDCP 1400 and the z platform axis 2230 is the depth of the MDCP1400.

FIG. 26 depicts a three dimensional top view of a mobile data collectionplatform 1400, according to one embodiment. FIG. 26 also depicts theentrance pupil center 1902, true north 2610, east 2203, the pointingvector PV, and the point of interest 2250. The projection of thepointing vector PV onto the horizontal plane gives the azimuth angle AZbetween the pointing vector PV and true north 2610. The azimuth angle AZis used as the tilt direction 2604, according to one embodiment, asdescribed herein.

According to one embodiment, z platform coordinate system is defined byx, y, z platform axes (or also referred to as “axes” of the “platformcoordinate system”) associated respectively with the three sides of amobile data collection platform 1400. The mobile data collectionplatform 1400 can be tilted with respect to one or more of the x, y andz platform axes 2240, 2220, and 2230 of the platform coordinate system.The tilt angle 2204 and tilt direction 2604 reflect the tilt of themobile data collection platform 1400 with respect to the one or more x,y and z platform axes 2240, 2220, 2230 of the platform coordinatesystem, according to one embodiment.

According to one embodiment, the image capturing device is in a knownspatial relationship with the mobile data collection platform. Forexample, one or more of the offsets 2406, 2501, 2502 depicted in FIG. 24and FIG. 26 or the offsets 2752 and 2751 in FIG. 27 can be used fordefining the known spatial relationship between the image capturingdevice and the mobile data collection platform. According to oneembodiment, the known spatial relationship is also a known physicalrelationship or a known physical spatial relationship.

The antenna-to-entrance-pupil-center-geometric-information may be usedto translate the GNSS position fix Xpf, Ypf, Zpf from the antenna 1412to the position of the entrance pupil center 1902 or vice versa. Anycombination of the GNSS position fix Xpf, Ypf, Zpf and the position X0,Y0, Z0 of the entrance pupil center 1902 can be related to each otherusing one or more of y axis offset 2406, x axis offset 2501, and z axisoffset 2502.

Referring to one or more of FIG. 24, FIG. 25 and FIG. 26, the GPSposition fix is a three dimensional position of and obtained from theantenna 1412 in the GNSS coordinate system. As depicted, the GPSposition fix is Xpf, Ypf, and Zpf respectively for latitude, longitudeand altitude. The local gravity vector 2270, true north 2610, and eastare respectively the Z local axis, the Y local axis and the X local axisof the local coordinate system. Note that the local coordinate frame,and the definition just given are not the same as the coordinate framefor the mobile data collection platform. However, data in one coordinatesystem may be translated into data in the other coordinate system, forexample, using known spatial relationships, as discussed herein. X0, Y0,Z0 is the three dimensional position of the entrance pupil center 1902in the local coordinate system. The known spatial relationship betweenthe antenna 1412 and the entrance pupil center 1902 and the orientationinformation, which includes the tilt angle 2204 and tilt direction 2604,can be used to translate the GPS position fix Xpf, Ypf, Zpf into thethree dimensional position X0, Y0, Z0 of the entrance pupil center 1902in the local coordinate system. The known spatial relationship (alsoknown as “antenna-to-entrance-pupil-center-geometric-information”)between the antenna 1412 and the entrance pupil center 1902 include oneor more of the y axis offset 2406, the x axis offset 2501, and the zaxis offset 2502.

By way of clarification, the side view of the mobile data collectionplatform in FIG. 23 shows a reference coordinate system for the platformand for the local coordinate system. This is further exemplified in FIG.22 where the platform coordinates are shown, and the world coordinatesas defined by the local coordinate system are shown.

The Mobile Data Collection Platform is not Required to be Level

According to one embodiment, the mobile data collection platform is notrequired to be level as a part of capturing an image 1452, determining aposition fix 1454 and determining orientation information 1456. Themobile data collection platform may be level if so desired. Leveling maybe obtained by adjusting the mobile data collection platform'sorientation using a support structure such as a tripod, and using thetilt information to determine a 90 degree platform angle relative to thegravity vector. For example, when both of the platform axes are 90degrees relative to the local gravity vector, then the mobile datacollection platform is level.

However, the mobile data collection platform is not required to be levelto determine a tilt angle, as is necessary in a more conventional totalstation. Further, the tilt angle 2204 is obtained directly 1 regardlessof any rotation of the mobile data collection platform with respect tothe pointing vector. When making measurements of objects on the groundor below the user, it may be useful to actually level the platform. Inthis case, both sides of the mobile data collection platform must beperpendicular to the local gravity vector, then the mobile datacollection platform is level. However, since the mobile data collectionplatform provides orientation information via the 2 or 3-axisaccelerometer and orientation system, it is not required to be level.

Scale Information Distance Between Point of Interest and Mobile DataCollection Platform

Referring to FIG. 24, scale information that may be used as a part ofdetermining a distance 2450 between the mobile data collection platform1400 and the point of interest 2250 can also be obtained. The scaleinformation may be the depiction of an object, which has a knowndimension, in the captured image. Examples of a known dimension arelength, width, and diameter that are known. For example, the dimensionsof a ruler or a quarter are known. E.g., a US quarter is 24.3 mm indiameter. In another example, a feature that appears in the image may bemeasured and the measurement may be used as the scale information. Morespecifically, one side of a window, a door, or side of a building, forexample, that appears in the image could be measured and used as scaleinformation. To do this with a single image capture, the camera must beon a pointing vector line that is perpendicular to the midpoint of thescale object. As this is hard to do, a second image may be captured andprocessed photogrammetrically. In yet another example, a second imagethat also depicts the point of interest is captured with the imagecapturing device at a second location where the first location and thesecond location are separated by a known distance. In this case, thescale information can include one or more of the first and secondimages, the first and second locations, such as position fixes, andorientations of the mobile data collection platform when the first andsecond images were captured, and the known distance between the firstand second locations where the two images were captured. The distancebetween the first and second locations may be determined from theposition fixes obtained at those two locations.

According to one embodiment, the scale information is any informationthat can be used in determining the distance between the point ofinterest 2250 (FIG. 22 and FIG. 24) and the three dimensional locationX0, Y0, Z0 (FIG. 24) of the entrance pupil center 1902. Scaleinformation can also be referred to as“distance-between-point-of-interest-and-mobile-data-collection-platform-information.”

According to one embodiment, scale information can be both the depictionof an object with at least one known dimension in an image 1452 and adistance between two positions P1, P2 that two images 1452 of a point ofinterest 2250 were captured from.

Aiming Aids Crosshairs and a Bubble Level

FIG. 27 depicts a graphical user interface 2700 that can be displayed onthe mobile data collection platform's display 1414, according to oneembodiment. As depicted in FIG. 27 and FIG. 28, the user is standingdirectly over the point of interest 2701 and taking an image 1452 of thepoint of interest 2701 with their mobile data collection platform 1400.The entrance pupil 1942 is located on the front of the mobile datacollection platform 1400. As depicted in FIG. 27, the mobile datacollection platform 1400's front is pointing downwards at the ground.2702, 2799 and 2701 are all within the field of view of the mobile datacollection platform 1400 and can be captured in an image 1452.

According to one embodiment, a mobile data collection platform includesa user interface 2700 that can be displayed on the mobile datacollection platform's display 1414. FIG. 27 depicts a user interface2700, according to one embodiment.

2712 is the approximate location of where the GNSS antenna is inside ofthe mobile data collection platform (MDCP) 1400. The GNSS antenna istypically near the top of the body of the MDCP 1400 and may be locatedanywhere along the top side of the MDCP 1400.

The user interface 2700 includes a crosshair display overlay 2721 (alsoreferred to as “crosshairs”) and a graphical bubble level overlay 2720(also referred to as “graphical bubble level” or “bubble level”).

The crosshair display overlay 2721 depicts a photographic image 2740 ofthe point of interest 2701. As depicted in FIG. 27, the photographicimage 2740 is not in the center 2750 of the intersection of the twocrosshairs but instead is slightly down and to the left of the center2750. If a photographic image of a point of interest is in the center2750 of the crosshair display overlay 2721, then the optical axis 2760from the entrance pupil center 1902 is in alignment with the point ofinterest 2701. The pointing vector PV is coaxial with the optical axis2760, according to one embodiment. According to one embodiment, if thephotographic image 2740 of a point of interest 2701 appears anywhere inthe crosshair display overlay 2721 when the user presses the accept databutton 2730, the point of interest 2701 is a user selected point ofinterest.

According to one embodiment, a mobile data collection platform 1400includes a bubble level processing logic 1820 and an image capturingdevice 1430. The better the mobile data collection platform 1400 itselfis aligned with a point of interest 2701, the better the accuracy of thedetermined position of the point of interest 2701 may be. In anembodiment, mobile data collection platforms that are equipped with bothan image capturing device 1430 and a tilt sensor 1442 may be used to aidin positioning the image capturing device 1430 more precisely over atarget point of interest 2701.

FIG. 27 shows the implementation of an aiming aid in a mobile datacollection platform which implements improved accuracy using the userinterface 2700 in accordance with one embodiment. Mobile data collectionplatform 1400 is depicted in a side view with a projection of the imagecapturing device 1430 to a top plan view. As can be seen from the planview and the side view, the display side of mobile data collectionplatform 1400 is oriented upward and the opposite side of mobile datacollection platform 1400, which includes an image capturing device 1430with an entrance pupil center 1902, is oriented downward toward a pointof interest 2701.

Referring now to FIG. 27, mobile data collection platform 1400 may beheld so it is looking downward, over the point of interest 2701 as isshown in FIG. 27. The image 1452 captured depicts, according to oneembodiment, the point of interest 2701, the object 2799 and thereference point 2702. In accordance with one embodiment, the bubblelevel processing logic 1820 provides an aiming/pointing aide such as agraphical bubble level overlay 2720 with a set of concentric circles orconcentric squares or other such visual aide around the center 2771 ofthe graphical bubble level overlay 2720 which can be displayed on thedisplay 1414 of mobile data collection platform 1400, when the imagecapturing device 1430 is activated and displaying an image 1452.According to one embodiment, the crosshair display overlay 2721 overlaysthe image 1452 displayed on the display 1414. Similarly, the tilt sensor1442 may have its output conditioned to display the degree of alignmentof the display 1414 with a horizontal plane, one that is perpendicularto a local gravity vector that represents ‘vertical.’ That is, tiltsensor 1442 may be used as an indicator of how level the body of mobiledata collection platform 1400 is, by indicating the tilt angles fromvertical in two dimensions, left-right and ‘up-down’ relative to theview screen of mobile data collection platform 1400 when it is heldhorizontally with the screen of display 1414 face up. The coordinatesare North-South and East-West, in the coordinate space. Alternatively,bubble level processing logic 1820 can display a graphical version of abubble level, such as the graphical bubble 2770 and the bubble leveloverlay 2720, in which a small circle representing a ‘bubble’ isconstrained to move within a pair of concentric circles, emulating amechanical bubble level. The graphical bubble position, as depicted bythe bubble 2770, within the pair of circles, as depicted by the bubblelevel overlay 2720, is moved in proportion to the degree of tilt in thetwo orthogonal axes 2780, 2781 of the mobile data collection platform1400.

In an embodiment, a single measurement of the degree of tilt fromvertical, given in degrees either from vertical, or from a horizontalplane from the tilt sensor 1442 may be displayed. The direction of thetilt angle as projected on a horizontal plane may be determined from thecompass heading, when the tilt of the body of the mobile data collectionplatform is aligned with the major axis of the body of the mobile datacollection platform.

In an embodiment, better accuracy in locating a desired point ofinterest 2701 may be obtained by incorporating the offset distance(e.g., offset 2752 of FIG. 27) between the entrance pupil center 1902 ofimage capturing device 1430 and the location of the GNSS/GPS antenna2711.

In the example depicted in FIG. 27, the photographic image 2740 of thepoint of interest 2701 is not yet in the exact center 2750 of the aimingcrosshairs of the crosshair display overlay 2721. Embodiments are wellsuited to the photographic image 2740 of the point of interest beinglocated in the center 2750 or not being located in the center 2750, asdiscussed herein. In FIG. 27, bubble level processing logic 1820 hasgenerated a graphical bubble level overlay 2720 to facilitate a user inaligning the mobile data collection platform 1400 relative to the localgravity vector.

In accordance with one embodiment, bubble level processing logic 1820can incorporate the offset distances 2751 and 2752 to more preciselydetermine the coordinates of the point of interest 2701, especially whenthe photographic image 2740 of the point of interest is in the center2750 of the crosshair display overlay 2721.

In one embodiment, the position of reference point 2702, and of mobiledata collection platform 1400 can be determined using photogrammetricprocessing of an image captured by mobile data collection platform 1400.For example, in accordance with one embodiment, mobile data collectionplatform 1400 can access a remotely located database of geo-taggedimages, wherein an image of the reference point 2702 is captured by theimage capturing device 1430 and delivered to the database of geo-taggedimages for matching using photogrammetric processing. Therefore,according to one embodiment, the reference point 2702 is what isreferred to as a “georeference point of interest” or a “georeferencefeature.” A position fix for a location of a georeference point ofinterest is referred to as a “georeference position fix.” For moreinformation about georeference points of interest or georeferencefeatures and georeference position fix, refer to U.S. 2011/0064312 filedon Sep. 14, 2009 entitled “Image-Based Georeferencing” by Janky et al,having Attorney Docket No, A2592, and assigned to the assignee of thepresent application. Once the reference point 2702 has been identifiedin the database, the coordinates of reference point 2702 can bedelivered from the database to mobile data collection platform 1400. Thecoordinates of the reference point 2702 may be three dimensionalcoordinates.

Object 2799 is an object of known width or dimensions that can be usedfor example as scale information. Since the object 2799 has a knownwidth or dimension, it can provide a scale that can be used fordetermining the distance between the point of interest 2701 and themobile data collection platform 1400.

Although FIG. 27 has been described in the context of mobile datacollection platform 1400, embodiments that pertain to FIG. 27 aresuitable for being used for other mobile data collection platforms, suchas 1500, as described herein.

FIG. 28 depicts a top down view of a field of view, according to oneembodiment. The field of view (FOV) 2800 correlates with the field ofview in FIG. 27 and, thus, includes a top down view of the reference2702, the object 2799, the real point of interest 2701 and a pseudopoint of interest 2898. According to one embodiment, the pseudo point ofinterest is represented as a pixel or a group of pixels in the capturedimage 1452.

According to one embodiment, the entrance pupil center 1902 is one endof the pointing vector 2760 and the pseudo point of interest 2898 islocated at the other end of the pointing vector 2760. Therefore,according to one embodiment, the pixel or group of pixels thatrepresents the pseudo point of interest 2898 would be located at thecrosshair display overlay 2721's center 2750.

The processing logic 1800 depicted in FIG. 18, shall now be discussed inthe context of FIGS. 27 and 28.

The crosshairs processing logic 1810 receives and processes informationwith respect to the crosshair display overlay 2721. For example, thecrosshairs processing logic 1810 can receive information indicating thata photographic image 2740 of a point of interest 2701 is inside of thecrosshair display overlay 2721 and use the received information to markthe point of interest 2701 as a user specified point of interest. Inanother example, the crosshair display overlay 2721 can be used tomeasure how closely the axis 2760 with respect to being in alignmentwith the point of interest 2701. For example, if the photographic image2740 is right in the center 2750, then the axis 060 is in alignment withthe point of interest 2701. If the photographic image 2740 is inside ofthe crosshair display overlay 2721 but off center, the crosshairsprocessing logic 1810 can measure how far the photographic image 2740 isfrom the center 2750 and in what direction. The measurement may be a twodimensional measurement since the crosshair display overlay 2721 is twodimensional.

The bubble level processing logic 1820 can receive information from thetilt sensor 1442 and use the received information to display a graphicalvisual representation of a bubble 2770 inside of the electronic bubblelevel overlay 2720. According to one embodiment, the bubble level 2720,2770 that is used, according to various embodiments, is not a physicalor mechanical bubble level that has a physical or mechanical bubble butinstead is a bubble level that is displayed in a graphical display (alsoreferred to herein as a “graphical bubble level”).

As depicted in FIG. 27, the mobile data collection platform 1400's frontis pointing downwards at the ground. However, embodiments are wellsuited to using the mobile data collection platform 1400 when the mobiledata collection platform 1400's front is facing forward and/orperpendicular to the ground, for example, as depicted in FIGS. 29-32.According to various embodiments, the bubble level 2720, 2770 can beused when the mobile data collection platform 1400 is facing downwardsas depicted in FIG. 27 or facing forward and/or perpendicular to theground as depicted in FIGS. 29-32. For example, a user can selectbetween a downward facing mode or a forward facing mode using agraphical user interface displayed on the mobile data collectionplatform's display 1414. If the downward facing mode is selected, thenthe bubble level 2720, 2770 can be in a downward facing orientation asdepicted in FIG. 27. If the forward facing mode is selected, then thebubble level 2720, 2770 can be used in a forward facing orientation aswould be the case for FIGS. 29-32.

According to one embodiment, the distance between two positionsprocessing logic 1840 obtains the position fixes associated with twolocations that a mobile data collection platform took images of a pointof interest and determines a distance between the two locations based onthe position fixes.

Methods of Using the Mobile Data Collection Platform

FIG. 29 depicts a three dimensional view of a mobile data collectionplatform that is being used to perform data collection, according to oneembodiment.

FIG. 29 depicts the altitude 2923 from the ground to the entrance pupilof the mobile data collection platform, a point of interest 2250located, for example, on a building, the local gravity vector 2270, truenorth 2201, a horizontal plane HP, which is about the entrance pupilcenter's three dimensional coordinates X0, Y0, Z0, a pointing vector PV,an azimuth angle AZ, and an elevation angle EL. In this example, truenorth defines the Y local axis 2201, the local gravity vector 2270defines the Z local axis 2202, and east defines the X local axis 2203.The three dimensional position X0, Y0, Z0 is in the local coordinatesystem, according to one embodiment. The horizontal plane HP is aboutthe position X0, Y0, Z0. The altitude 2923 is the distance betweenground level and the entrance pupil center 1902 of the mobile datacollection platform. The altitude 2923 is the same as Z0 for theposition associated with the mobile data collection platform. Thepointing vector PV points from the mobile data collection platform'sentrance pupil center to the point of interest 2250. The pointing vectorPV is oriented along the image capturing device's axis 2760 (FIG. 27)from the entrance pupil of the mobile data collection platform.

FIG. 29 depicts a first line 2920 between the point of interest 2250 anda second point 2922 that is positioned at the altitude 2923 of theentrance pupil center above ground level. The first line 2920 isparallel to the local gravity vector 2270. FIG. 29 depicts a second lineHL (also referred to herein as “horizontal line HL”) that is horizontalfrom the entrance pupil center to the second point 2922. FIG. 29 depictsthe azimuth angle AZ which is the angle between true north 2201 and thesecond line HL. FIG. 29 depicts the elevation angle EL is the anglebetween the second line HL and the pointing vector PV. The horizontalplane HP includes the second line HL, according to one embodiment.

Referring to FIG. 29, the image 1452 taken with a mobile data collectionplatform associated with the coordinates X0, Y0, Z0 (FIG. 24), accordingto one embodiment, includes the point of interest 2250 and the object2930. The object 2930 is an object of a known dimension, such as one ormore of width, diameter, length, that can be used, for example, as scaleinformation, as described herein. For example, the object 2930 could bea yardstick. The object 2930 could be affixed to the wall by theoperator of the Mobile Data Collection Platform 1400.

FIG. 30 depicts the same scene depicted in FIG. 29 from a top view,according to one embodiment.

FIG. 30 depicts the azimuth angle AZ between the pointing vector PV andtrue north, which is used as the Y local axis 2201. The first dashedline 3010 represents the shortest distance between the point of interest2250 and Y local axis 2201 representing true north. The second dashedline 3020 represents the shortest distance between the point of interest2250 and X local axis 2203 representing east. Ypt is the point where thefirst dashed line 3010 intersects the Y local axis 2201. Xpt is thepoint where the second dashed line 3020 intersects the X local axis2203. The first dashed line 3010 and the second dashed line 3020 form aright angle where they meet at the point of interest 2250. According toone embodiment, all four of the corners formed by the Y local axis 2201,the X local axis 2203 and the dashed lines 3010, 3020 form right angles.The first dashed line 3010 and the line between X0, Y0, Z0 and Xpt arethe same length. The second dashed line 3020 and the line between X0,Y0, Z0 and Ypt are the same length. The intersections of the dotted line3010 and 3020 with the two X and Y local coordinate axes 2203, 2201 givethe coordinates Xpt, Ypt of the point of interest 2250. These coordinatepositions Xpt, Ypt may be obtained by application of well-knowntrigonometric principles, once the radial distance between X0, Y0, Z0and the point of interest 2250 along the pointing vector PV has beendetermined.

FIG. 31 depicts a side view of the same scene depicted in FIGS. 29-49from a side view, according to one embodiment.

FIG. 31 depicts the mobile data collection platform 1400, the altitude2923, the elevation angle EL, the pointing vector PV, the second lineHL, the point of interest 2250, the building, the distance 2260, thetilt direction 2604, and the tilt angle 2204. The point of interest 2250is located on the building. The coordinates of the point of interest2250 in this example are Xpt, Ypt, and Zpt. The altitude 2923 is thedistance between the ground level 3110 and the second line HL, alsoknown as the horizontal line HL. The distance 2260 is the distancebetween the second point 2922 where the second line HL interests thebuilding and the point of interest 2250. The altitude 2923 plus thisdistance 2260 is the altitude Zpt of the point of interest 2250 abovethe ground level 3110, which can be expressed as Zpt=Z0+PV·sin(EL).According to one embodiment, Zpt is equal to the altitude 2923 plus thedistance 2260.

Z0 is the point where the pointing vector PV and the local gravityvector 2270, which represents the Z local axis 2202, intersect. The tiltangle 2204 is the angle between the entrance pupil center and the localgravity vector 2270 represented by the Z local axis 2202. The tiltdirection 2604 indicates the direction the mobile data collectionplatform 1400 is tilted with respect to the local gravity vector 2270.In this example, the top of the mobile data collection platform 1400 isfurther back than the bottom of the mobile data collection platform1400.

FIG. 32 depicts a top view of a scene where a mobile data collectionplatform is used to take two images of a point of interest, according toone embodiment.

FIG. 32 depicts true north 3202, 3206 and east 3203, which can beobtained using the compass 1444. The user orients, according to oneembodiment, the mobile data collection platform so that the compass 1444display reads as close to 0 degrees as possible.

The radial distance between distance D 3201 and the point of interest2250 may be determined once observations are taken at two spaced apartlocations P1 and P2 for the mobile data collection platform. Theprinciples are well known in the photogrammetric arts. As depicted inFIG. 32, a first image of the point of interest 2250 is taken atposition P1 and a second image of the point of interest 2250 is taken atposition P2. The two positions P1 and P2 are separated by a distance D3201 (also referred to as the distance line D K01). According to oneembodiment, the distance between two positions processing logic 1840obtains the position fixes associated with two locations P1, P2 that amobile data collection platform took images of a point of interest 2250and determines the distance D 3201 between the two locations P1, P2based on the position fixes. Respective first and second orientationinformation of the mobile data collection platform is associated withthe positions P1 and P2. FIG. 32 depicts respective pointing vectors PV1and PV2 from the entrance pupil center 1902 to the point of interest2250 for the respective positions P1 and P2.

As depicted in FIG. 32, there is a first line 3202 from P1 in thedirection of true north (also referred to as “first true north line”)and a second line 3206 from P2 in the direction of true north (alsoreferred to as “second true north line”). The two lines 3202 and 3206are parallel to each other since they are both in the direction of truenorth. Both of the lines 3202 and 3206 are perpendicular to the line3201 that represents the distance D. These are examples for the sake ofexplanation. The directions may be arbitrarily chosen.

FIG. 32 depicts several angles. The first azimuth angle AZ1 is betweenpointing vector PV1 and the first true north line 3202, a second azimuthangle AZ2 is between pointing vector PV2 and the second true north line3206. Azimuth angle AZ1 is the compass 1444′ angle from true north 3202to the point of interest 2250 and Azimuth angle AZ2 is the compass 1444′angle from true north 3206 to the point of interest 2250. According toone embodiment, angle A is at least 20°. According to one embodiment,angle A ranges between 20° and 30° but can be any number of degrees.

The three dimensional coordinates of the positions P1 and P2 are GPSpositions and are known. The GPS three dimensional coordinates for P1are X1, Y1, Z1. The GPS three dimensional coordinates for P2 are X2, Y2,Z2. P1 and P2 are three dimensional positions in the GNSS coordinatesystem. Distance D 3201 can be calculated by subtracting the GPSposition fixes X1, Y1, Z1 for P1 and X2, Y2, Z2 for P2 using the vectorequation D=P1-P2.

Referring to FIG. 32, the scale information can include one or more ofthe first image taken from P1 and the second image taken from P2, thefirst coordinates X1, Y1, Z1 for the location P1, the second coordinatesX2, Y2, Z2 for the location P2, the respective orientations of themobile data collection platform when it captured images at P1 and P2,and the known distance D 3201 between the first location P1 and thesecond location P2.

According to one embodiment, scale information can be both the depictionof an object 2799, 2930 with at least one known dimension in an image1452 and a distance D 3201 between two positions P1, P2 that two images1452 of a point of interest 2250 were captured from.

The two images, position fixes of the MDCP when at positions P1 and P2,orientation information of the MDCP at positions P1 and P2, and thedistance D 3201 can be stored in the hardware memory 1450.

Methods of Using a Graphical Bubble Level and Crosshairs

The following descriptions of FIG. 33 and FIG. 34 refer to FIG. 27.

FIG. 33 is a flowchart of a method 3300 for generating a bubble leveloverlay 2720 on a display in accordance with one embodiment. Inaccordance with various embodiments, the operations described in FIG. 33are controlled using bubble level processing logic 1820.

At 3301, the display of the graphical bubble level overlay 2720 andgraphical bubble 2770 on the display 1414 is activated.

At 3302 the tilt sensor 1442 is reset, for example, by zeroing the tiltsensor 1442 on a reference level surface.

At 3303 tilt and orientation information is obtained. For example, thetilt angle 2204 and tilt direction 2604 can be obtained respectivelyfrom the tilt sensor 1442 and the compass 1444.

At 3304 the tilt angle 2204 is converted relative to the local gravityvector 2270.

At 3305 the position of the bubble 2770 for display on the display 1414is calculated.

At 3306 the bubble 2770 is displayed in the measured position, which wascalculated at 3305, on display 1414.

At 3307 the display of the bubble 2770 on display 1414 is updated inreal-time as new Euler angles are obtained from the tilt sensor 1442.

FIG. 34 is a flowchart of a method 3400 for implementing an aiming aidoperation in accordance with one embodiment. According to oneembodiment, the crosshair display overlay 2721 and bubble 2770 arecontrolled by the crosshairs processing logic 1810.

At 3401, the aiming aid operation is activated from a menu selection.

At 3402 a position determination mode is selected. In accordance withone embodiment, if no position determination mode is selected, the lastoperating position fix system is automatically selected.

At 3403 crosshair display overlay 2721 is displayed on the display 1414.

At 3404 the graphical bubble level is activated.

At 3405 the graphical bubble level overlay 2720 is displayed with thegraphical bubble 2770.

At 3406 the accept data button 2730 is enabled.

At 3407 Euler angles from the tilt sensor 1442 are stored, for example,in hardware memory 1450 as the Euler angles become available.

Methods of Performing Data Collection Using a Mobile Data CollectionPlatform

FIG. 35 depicts a flowchart 3500 of a method of performing datacollection using a mobile data collection platform, according to oneembodiment.

At 3510, the method begins.

At 3520, an image 1452 that includes at least one point of interest 2250is captured where an image capturing device 1430 that is part of themobile data collection platform 1400 captures the image 1452.

At 3530, raw observables for the mobile data collection platform 1400are obtained. For example, a GNSS chipset 1413 of the mobile datacollection platform 1400 is accessed and raw observables are extractedfrom the mobile data collection platform 1400's GNSS chipset 1413. Inanother example, the raw observables are received by the mobile datacollection platform 1400 from an optional external GNSS raw observableprovider 3750 (FIG. 37). A mobile data collection platform 1400 can usethe raw observables received from the optional external GNSS rawobservable provider even if the mobile data collection platform 1400 hasan internal GNSS chipset 1413.

The raw observables, from either the internal GNSS chipset 1413 or theexternal GNSS raw observable provider 3750, are for use outside the GNSSchipset 1413 and elsewhere in the mobile data collection platform 1400,for example, in a supl client as discussed herein. Other examples ofoutside the GNSS chipset 1413 and elsewhere in the mobile datacollection platform 1400 include processing logic 1480, 1570, and 1800.Examples of for use elsewhere include being executed by a hardwareprocessor 1460 that is inside the mobile data collection platform 1400and outside of the GNSS chipset 1413. According to one embodiment, thehardware processor 1460 executes the processing logic 1480, 1570, and1800.

At 3540, a position fix Xpf, Ypf, Zpf (FIG. 24) of the mobile datacollection platform 1400 is determined based on the raw observables. Forexample, the raw observables that are extracted from the GNSS chipset1413 can be processed, according to various embodiments, describedherein, to determine a position fix Xpf, Ypf, Zpf. The position fix Xpf,Ypf, Zpf, according to one embodiment, provides a location of the mobiledata collection platform 1400 in a GNSS coordinate system.

Various embodiments described herein can be used for smoothingpseudoranges, correcting pseudoranges before determining the positionfix Xpf, Ypf, Zpf, as described herein. Various embodiments can be usedfor applying locally measured movement information to a position fix ofthe antenna 1412 to determine a locally measured movement smoothedposition fix. In this case, the position fix Xpf, Ypf, Zpf is a locallymeasured movement smoothed position fix. Examples of a locally measuredmovement smoothed position fix are 2665B, 2691D, and 2675F.

At 3550, orientation information comprising tilt angle and azimuth angleare determined.

For example, the orientation information can be obtained from one ormore sensors 1442, 1444 that are part of the mobile data collectionplatform 1400. Orientation information can include tilt angle 2204 (FIG.24), and azimuth angle AZ (FIG. 26), as discussed herein. According toone embodiment, Euler angles are obtained from the tilt sensor 1442 andtranslated into the tilt angle 2204. The azimuth angle AZ can beobtained based on information from the compass 1444.

The tilt angle 2204 and the azimuth angle AZ can be determined based ondata from an accelerometer type tilt sensor 1442. An accelerometer typetilt sensor 1442 is able to determine the tilt angle 2204 of thesensor's X and Y axis relative to gravity, in addition to determiningthe tilt angle 2204. The tilt angle 2204 is often used to mean both ofthe sensor's X and Y axis. The magnetic sensor triad of theaccelerometer type tilt sensor 1442 can then be used to determine theazimuth angle AZ. For more information, refer to “Tilt Measurement Usinga Low-g 3-axis Accelerometer” published April 2010 document ID 17289 Rev1 (also known as AN3461 from Freescale).

The tilt angle 2204 (FIG. 24) is between the mobile data collectionplatform 1400 and a local gravity vector 2270, and the azimuth angle AZ(FIG. 26) is between true north 2610 and a pointing vector PV of themobile data collection platform. The position fix Xpf, Ypf, Zpf (FIG.24) and the orientation information are associated with a threedimensional location X0, Y0, Z0 (FIG. 24) of the mobile data collectionplatform 1400 when the image 1452 was captured. According to oneembodiment, the three dimensional location X0, Y0, Z0 is the threedimensional position of the entrance pupil center 1902 (FIG. 24).

The mobile data collection platform 1400 is not required to be leveled,as discussed herein.

The position fix Xpf, Ypf, Zpf (FIG. 24) and the orientation can beassociated with the image 1452 by the mobile data collection platform1400's user holding the mobile data collection platform 1400 in the sameposition during the capturing of the image 1452, the determining of theposition fix Xpf, Ypf, Zpf and the determining of the orientation,according to one embodiment. Examples of orientation are the tilt angle2204 (FIG. 24) and the tilt direction (also known as the “azimuthangle”) 2604 (FIG. 26). In another example, the position fix 1454 andthe orientation information 1456 can be associated with the image 1452by simultaneously or nearly simultaneously capturing of the image 1452,determining of the position fix Xpf, Ypf, Zpf and determining of theorientation information 1456. An example of nearly simultaneously isperforming the capturing of the image 1452, determining of the positionfix Xpf, Ypf, Zpf and determining of the orientation information 1456 ina short period of time where user movement is small to non-existent.More specifically, modern electronics are capable of performing thecapturing of the image 1452, the determining of the position fix Xpf,Ypf, Zpf and the determining of the orientation information 1456 within0.25 second, for example, in response to a button of the mobile datacollection platform 1400, 1500 being pressed. Alternatively, a timer canbe used instead of the button to trigger performing the capturing of theimage 1452, the determining of the position fix Xpf, Ypf, Zpf and thedetermining of the orientation information 1456 within 0.25 second, forexample.

At 3560, scale information is captured.

One example of scale information is an object 2799 (FIG. 27), 2930 (FIG.29) depicted in the image 1452 where the object 2799 has one or moreknown dimensions. The depiction of the scale information in the image isan example of capturing the scale information. Referring to FIG. 32,another example of scale information is the known distance D 3201between two positions P1, P2 where two respective images 1452 werecaptured where both images 1452 depict of the point of interest 2250.For example, the first image 1452, which depicts the point of interest2250, may be captured with an image capturing device 1430 from positionP1 and the second image 1452, which also depicts the point of interest2250, may be captured with the mobile data collection platform 1400 fromposition P2. Examples of capturing the known distance D 3201 are aperson determining or measuring the distance D 3201 or determining thedistance D 3201 by subtracting a first position fix of the mobile datacollection platform 1400 for a the first position P1 from a secondposition fix of the MDCP 1400 for the second position P2.

At 3570, the image 1452, the position fix Xpf, Ypf, Zpf, the scaleinformation, and the orientation information 1456 are stored in hardwarememory 1450 of the mobile data collection platform. The position fixXpf, Ypf, Zpf is stored as position fix 1454. The image, the positionfix and the orientation information 1456 can be used to determine alocation of a point of interest 2250 in the image 1452 using, forexample, photogrammetry. Photogrammetry is well known in the arts.According to one embodiment, the image 1452, the position fix 1454 andthe orientation information 1456 can be used to determine a threedimensional location Xpt, Ypt, Zpt of the point of interest 2250.According to one embodiment, the three dimensional location Xpt, Ypt,Zpt of the point of interest 2250 is determined in the local coordinatesystem.

At 3580, the method ends.

According to one embodiment, the method 3500 can be performed, forexample, within a fraction of a second so that the mobile datacollection platform is at the position fix Xpf, Ypf, Zpf and in theorientation described by orientation information 1456 at the time thatthe image 1452 is captured.

Various embodiments provide for capturing depiction an object 2799 (FIG.27), 2930 (FIG. 29) with at least one known dimension, wherein the image1452 depicts the object 2799 (FIG. 27), 2930 (FIG. 29) with the at leastone known dimension.

Various embodiments provide for capturing a first image 1452 and asecond image 1452 that both depict the point of interest 2250, whereinthe first image 1452 is captured from a first position P1 and the secondimage 1452 is captured from a second position P2 and for calculating adistance D 3201 between the first position P1 and the second positionP2.

Various embodiments provide for determining a first position P1, whereinthe first position P1 is selected from a group consisting of a positionof a georeference point of interest 2702, and a position fix Xpf, Ypf,Zpf of the mobile data collection platform 1400 where the point ofinterest 2701, 2250 is in a field of view 2800 of the image capturingdevice 1430; determining a second position P2, wherein the secondposition P2 is selected from the group consisting of the position of thegeoreference point of interest 2702, and the position fix Xpf, Ypf, Zpfof the mobile data collection platform 1400 where the point of interest2701, 2250 in the field of view 2800; and determining a referencedistance D 3201 between the first position P1 and the second positionP2.

An embodiment provides for determining the orientation informationcomprising the tilt angle and the azimuth angle, wherein the tilt angleis between a y platform axis of the mobile data collection platform anda local gravity vector, and the azimuth angle is between a referencedirection and a pointing vector of the mobile data collection platform.For example, the determined orientation information 1456 can include thetilt angle 2204 and the azimuth angle AZ, wherein the tilt angle 2204 isbetween a y platform axis 2220 of the mobile data collection platform1400 and a local gravity vector 2270, and the azimuth angle AZ isbetween a reference direction, such as magnetic north or true north2610, and a pointing vector PV of the mobile data collection platform1400.

According to one embodiment, the pointing vector PV is in a knownorientation relative to a compass heading, such as magnetic north.According to one embodiment, the pointing vector PV is aligned with thecompass heading.

According to one embodiment, the pointing vector PV is aligned with thecompass heading. For example, the user of the mobile data collectionplatform can hold the MDCP so that the pointing vector PV is alignedwith the compass heading from the compass 1444.

Various embodiments provide for capturing angular displacement from afirst point on a scalar reference to a second point on the scalarreference visible in a field of view as given by a pixel count from thefirst point to the second point. For example, the angular displacementfrom one end of a scalar reference 2799 (FIG. 27), 2930 (FIG. 29) to theother end of the scalar reference 2799 (FIG. 27), 2930 (FIG. 29) visiblein the field of view of an image 1452 can be captured by counting thepixels from the one end to the other end of the scalar reference 2799(FIG. 27), 2930 (FIG. 29).

Various embodiments provide for calibrating the mobile data collectionplatform by determining a pixel calibration datum providing the angulardisplacement of each pixel, in two dimensions, depicted in a calibrationimage taken with the image capturing device. For example, according toone embodiment, the mobile data collection platform 1400, 1500 can becalibrated by determining a pixel calibration datum 2050 (FIG. 20)providing the angular displacement of each pixel in a calibration image2160 (FIG. 21) in two dimensions, where the calibration image 2160 istaken with an image capturing device 1430 (FIG. 14) of a pattern 2010(FIG. 20).

Various embodiments provide for calibrating the mobile data collectionplatform by determining an acceptable region in a calibration imagetaken with the image capturing device, wherein the acceptable regionincludes a subset of pixels of the calibration image where the pixels donot exceed a specified level of distortion (also known as an “acceptablelevel of distortion”). For example, according to one embodiment, themobile data collection platform 1400 is calibrated by determining anacceptable region 2140 in a calibration image 2160 taken with the imagecapturing device 1430 that includes a subset of the calibration image2160's pixels that do not exceed an acceptable level of distortion.According to one embodiment, the acceptable region 2140 includes asubset of the calibration image 2160's pixels because the pixels in theunacceptable region 2190 that is between the boundary 2180 of theacceptable region 2140 and the periphery 2185 of the calibration image2160 are not included in the subset.

Various embodiments provide for receiving outline information describingan outline of the point of interest; and designating the point ofinterest as a user specified point of interest based on the outlineinformation. For example, according to one embodiment, outlineinformation describing an outline of the point of interest 2250 isreceived and the point of interest 2250 is designated as a userspecified point of interest based on the outline information.

Various embodiments provide for designating the point of interest as auser specified point of interest based on orientation information fromcrosshairs processing logic associated with the mobile data collectionplatform when crosshairs are aligned with the point of interest and animage capture button is pressed. For example, according to oneembodiment, designating the point of interest 2250 as a user specifiedpoint of interest based on orientation information 1456 from theorientation system 1470 associated with the mobile data collectionplatform 1400 when the crosshairs of the crosshair display overlay 2721are aligned with the point of interest 2250 and an image capture buttonis pressed to capture the image 1452.

Various embodiments provide for designating the point of interest as auser specified point of interest based on an annotation from an imageeditor associated with the mobile data collection platform. For example,according to one embodiment, the point of interest 2250 is designated asa user specified point of interest based on an annotation from an imageeditor 1778 associated with the mobile data collection platform 1400,1500.

Various embodiments provide for receiving annotation information; andassociating the annotation information with the image. For example,according to one embodiment, the annotation information is received andassociated with the image 1452. The annotation information can beassociated with the image using an EXIF file. The annotation informationcan be associated with the file using other techniques that are wellknown in the art, such as tables, pointers, identifiers.

Various embodiments provide for performing feature identification on atleast a subset of the image. For example, according to one embodiment,feature identification 1774 is performed on at least a subset of theimage 1452.

Various embodiments provide for performing pattern recognition on atleast a subset of the image. For example, according to one embodiment,pattern recognition 1776 is performed on at least a subset of the image1452.

Various embodiments provide for displaying crosshair display overlay ona display of the mobile data collection platform; displaying aphotographic image of the point of interest in relation to the crosshairdisplay overlay; and positioning the photographic image with respect tothe crosshair display overlay based on an alignment of an entrance pupilof the mobile data collection platform with the point of interest. Forexample, according to one embodiment, crosshair display overlay 2721 isdisplayed on a display 1414 of the mobile data collection platform 1400;a photographic image 2740 of the point of interest 2701 positioned inrelation to the crosshair display overlay 2721; and the photographicimage 2740 is displayed with respect to the crosshair display overlay2721 based on an alignment of an entrance pupil center 1902 of themobile data collection platform 1400 with the point of interest 2701.

Various embodiments provide for displaying a bubble level overlay on adisplay of the mobile data collection platform; displaying a graphicalbubble in relation to the bubble level overlay; and positioning thegraphical bubble with respect to the bubble level overlay based on adegree of tilt of the mobile data collection platform. For example,according to one embodiment, a bubble level overlay 2720 is displayed ona display 1414 of the mobile data collection platform 1400; a graphicalbubble 2770 is displayed in relation to the bubble level overlay 2720;and the graphical bubble 2770 is positioned with respect to the bubblelevel overlay 2720 based on a degree of tilt, for example of twoorthogonal axes 2780, 2781, of the mobile data collection platform 1400.

According to various embodiments, determining a known spatialrelationship between an entrance pupil of the image capturing device andan antenna of the mobile data collection platform based on one or moregeometric offsets between the entrance pupil and the antenna. Forexample, according to one embodiment, a known spatial relationshipbetween an entrance pupil center 1902 of the image capturing device 1430and an antenna 1412 of the mobile data collection platform 1400 isdetermined based on one or more geometric offsets 2406 (FIG. 24), 2501,2502 (FIG. 26) between the entrance pupil center 1902 and the antenna1412 (FIG. 24 and FIG. 26).

FIG. 36 depicts a flowchart of a method 3600 of performing datacollection using a mobile data collection platform, according to oneembodiment.

According to one embodiment, as described herein, a mobile datacollection platform 1400 is a cellular device.

At 3610 the method starts.

At 3620, an image that depicts a point of interest is captured using acellular device. For example, the image 1452 that depicts the point ofinterest 2250 may be captured using the image capturing device 1430.

At 3630, a three dimensional position associated with the cellulardevice is determined based on a local gravity vector and a position fixof the cellular device.

For example, the local gravity vector 2270 (FIG. 24) can be determinedusing the information from the tilt sensor 1442 (FIG. 14). The positionfix Xpf, Ypf, Zpf, which is the location of the antenna 1412 accordingto one embodiment, can be determined and stored as position fix 1454(FIG. 14) can be determined as described herein.

An example of a three dimensional position associated with the MDCP 1400(FIG. 14) is the three dimensional position X0, Y0, Z0 (FIG. 24) of theentrance pupil center 1902 (FIG. 24) that is determined based on a localgravity vector 2270 and the position fix Xpf, Ypf, Zpf. The threedimensional position X0, Y0, Z0 is in the local coordinate system andthe local gravity vector 2270 is one of the axes of the local coordinatesystem.

Referring to FIG. 24 and FIG. 25, the local gravity vector 2270, truenorth 2610 and east 2203 respectively are the Z local axis 2202 (alsoknown as the local gravity vector 2270), the Y local axis 2201, 2610,and the X local axis 2203 for the local coordinate system. The GPSposition fix Xpf, Ypf, Zpf is a three dimensional position of theantenna 1412 in the GNSS coordinate system. The entrance pupil center1902 has a three dimensional position X0, Y0, Z0 in the local coordinatesystem. One or more of theantenna-to-entrance-pupil-center-geometric-information, the tilt angle2204, the tilt direction 2604 and the local gravity vector 2270 can beused to translate the GPS position fix Xpf, Ypf, Zpf in the GNSScoordinate system into the entrance pupil center 1902's threedimensional location X0, Y0, Z0 in the local coordinate system.

In another example, a GPS position fix can be determined based on rawobservables obtained from an optional external GNSS raw observableprovider 3750 (FIG. 37). Known spatial relationship, as discussedherein, between an antenna 3810 of the optional external GNSS rawobservable provider 3750 and the entrance pupil center 1902 of the MDCP1400 can be used to determine the three dimension location X0, Y0, Z0 ofthe entrance pupil center 1902 in the local coordinate system.

At 3640, scale information is captured.

One example of scale information is an object 2799 (FIG. 27), 2930 (FIG.29) depicted in the image 1452 where the object 2799 has one or moreknown dimensions. The depiction of the scale information in the image isan example of capturing the scale information. Referring to FIG. 32,another example of scale information is the known distance D 3201between two positions P1, P2 where two respective images 1452 werecaptured where both images 1452 depict of the point of interest 2250.For example, the first image 1452, which depicts the point of interest2250, may be captured with an image capturing device 1430 from positionP1 and the second image 1452, which also depicts the point of interest2250, may be captured with the image capturing device 1430 from positionP2. Examples of capturing the known distance D 3201 are a persondetermining or measuring the distance D 3201 or determining the distanceD 3201 by subtracting a first position fix of the MDCP 1400 for a thefirst position P1 from a second position fix of the MDCP 1400 for thesecond position P2.

At 3650, the image, the scale information and the three dimensionalposition are stored in hardware memory. For example, the image 1452, thescale information and the three dimensional position X0, Y0, Z0 can bestored in hardware memory 1450 of the mobile data collection platform1400.

The local gravity vector 2270 is local with respect to the MDCP 1400,for example, as depicted in FIG. 24.

The MDCP 1400 is at the position fix when the image 1452 is captured.Therefore, the entrance pupil center 1902, the antenna 1412, or theantenna 3810 are at the three dimensional position when the image 1452is captured.

The MDCP 1400 is not required to be perpendicular to the local gravityvector 2270 at the time of collecting of data. For example, none of theplatform axis 2220, 2230, 2240 of cellular device z00 are required to beperpendicular to the local gravity vector 2270 at the time of thecapturing of the image 1452 and the determining of the three dimensionalposition X0, Y0, Z0.

At 3660, the method ends.

According to one embodiment, the method 3600 can be performed, forexample, within a fraction of a second so that the mobile datacollection platform is at the position fix, which would be of eitherantenna 1412 or antenna 3810, and in the orientation described byorientation information 1456 at the time that the image 1452 iscaptured.

According to various embodiments, method 3600 is performed by a mobiledata collection platform and outside of the internal GNSS chipset 1413.Although many embodiments are described herein in the context of amobile data collection platform 1400, various embodiments are also wellsuited for mobile data collection platform 1500.

Either method 3500 or 3600 can be used with use cases depicted in FIGS.29-32. Either method 3500 or 3600 can be used for performing datacollection at position P1 and position P2 as depicted in FIG. 32. Forexample, method 3500 or 3600 could be used at position P1 to performdata collection and used at position P2 to perform data collection.

According to one embodiment, “capturing” an item, such as an image,scale information, distance, angular displacement and so on, includes“storing” the item, for example, in hardware memory, such as hardwarememory 1450.

Referring to FIG. 24 and FIG. 26, according to one embodiment, the tiltangle 2204 is between the mobile data collection platform 1400 and alocal gravity vector 2270, and the azimuth angle AZ is between areference direction, such as true north 2610, and a pointing vector PVof the mobile data collection platform 1400.

Various embodiments provide for obtaining a tilt angle and a tiltdirection of the cellular device; and determining the three dimensionalposition associated with the cellular device based at least in part onthe tilt angle and the tilt direction in relation to the local gravityvector. For example, according to one embodiment, a tilt angle 2204 anda tilt direction 2604 of the MDCP 1400 are obtained and the threedimensional position X0, Y0, Z0 associated with the MDCP 1400 isdetermined based at least in part on the tilt angle 2204 and the tiltdirection 2604 in relation to the local gravity vector 2270.

Various embodiments provide for determining the three dimensionalposition associated with the cellular device based at least in part ongeometric information relating an antenna of the cellular device with anentrance pupil center of the cellular device. For example, according toone embodiment, the three dimensional position X0, Y0, Z0 associatedwith the MDCP 1400 is determined based at least in part on geometricinformation, such as 2406, 2501, 2502, relating an antenna 1412 of theMDCP 1400 with an entrance pupil center 1902 of the MDCP 1400, forexample, as depicted in FIG. 24 and FIG. 25.

Various embodiments provide for designating the point of interest as auser specified point of interest based on information selected from agroup consisting of annotation from an image editor, an outline of thepoint of interest, and a photographic image of the point of interestbeing visibly displayed within crosshair display overlay. For example,according to one embodiment, the point of interest 2250 is designated asa user specified point of interest based on information selected from agroup consisting of annotation from an image editor 1778, an outline ofthe point of interest 2250, and a photographic image 2740 of the pointof interest 2701 being visibly displayed within crosshair displayoverlay 2721.

Various embodiments provide for displaying crosshair display overlay ona display of the cellular device; displaying a photographic image of thepoint of interest in relation to the crosshair display overlay; andpositioning the photographic image with respect to the crosshair displayoverlay based on an alignment of an entrance pupil of the cellulardevice with the point of interest. For example, according to oneembodiment, crosshair display overlay 2721 is displayed on a display1414 of the MDCP 1400; a photographic image 2740 of the point ofinterest 2701 is positioned in relation to the crosshair display overlay2721; and the photographic image 2740 is displayed with respect to thecrosshair display overlay 2721 based on an alignment of an entrancepupil center 1902 of the MDCP 1400 with the point of interest 2701.

Various embodiments provide for displaying a bubble level overlay on adisplay of the cellular device; displaying a graphical bubble inrelation to the bubble level overlay; and positioning the graphicalbubble with respect to the bubble level overlay based on a degree oftilt of the cellular device. For example, according to one embodiment, abubble level overlay 2720 is displayed on a display 1414 of the mobiledata collection platform 1400; a graphical bubble 2770 is displayed inrelation to the bubble level overlay 2720; and the graphical bubble 2770is positioned with respect to the bubble level overlay 2720 based on adegree of tilt, for example of two orthogonal axes 2780, 2781, of theMDCP 1400.

Various embodiments provide for determining a first position, whereinthe first position is selected from a group consisting of a position ofa georeference point of interest, and a position fix of the cellulardevice; determining a second position, wherein the second position fixis selected from the group consisting of the position of thegeoreference point of interest, and the position fix of the cellulardevice; and determining a distance between the first position and thesecond position. For example, according to one embodiment, a firstposition and a second position are determined where the first positionand the second position are selected from a group consisting of aposition of a georeference point of interest 2702, and a position fixXpf, Ypf, Zpf of the mobile data collection platform 1400; anddetermining a distance between the first position and the secondposition.

Various embodiments provide for determining a known spatial relationshipbetween an entrance pupil center of the cellular device and an antennaof the cellular device based on one or more geometric offsets betweenthe entrance pupil center and the antenna. For example, according to oneembodiment, a known spatial relationship between an entrance pupil ofthe image capturing device and an antenna of the cellular device isdetermined based on one or more geometric offsets 2406 (FIG. 24), 2501,2502 (FIG. 26) between the entrance pupil center 1902 and the antenna1412 (FIG. 24 and FIG. 26).

According to one embodiment, the MDCP 1400 is not required to beperpendicular to the local gravity vector 2270 at the time of thecapturing and the determining of the three dimensional position X0, Y0,Z0.

Mobile Data Collection Platform

FIG. 37 depicts a block diagram of a mobile data collection platformsystem, according to one embodiment. The mobile data collection platformsystem includes a mobile data collection platform 3700 and an externalGNSS raw observable provider 3750 that is outside of the mobile datacollection platform 3700. The mobile data collection platform 3700 caninclude any one or more features of MDCP 1400, 1500.

The mobile data collection platform 3700 includes a bus 3710, varioustypes of software 3701, one or more hardware processors 1460, computerusable non-volatile memory (ROM) 3702, computer usable volatile memory(RAM) 3703, hardware memory 1450 that includes data 3704, a display1414, a graphical user interface (GUI) 3705, input/output device 3706,platform orientation system 1470, cellular communications 1510, othercommunications receivers 3707, image capturing device 1430, bubble levelsystem 1820, and short range communications 3709.

The software 3701 is connected with the RAM 3703 and the memory 1450.

The bus 3710 is connected with the one or more processors 1460, the ROM3702, the RAM 3703, the memory 1450, the display 1414, the GUI 3705, theinput/output device 3706, the platform orientation system 1470, thecellular communications 1510, the other communications receivers 3707,the image capturing device 1430, the bubble level system 1820 and theshort range communications 3709. The MDCP 3700 can communicate with anoptional external GNSS raw observable provider 3750 and a peripheralcomputer readable storage media 3760.

Examples of software 3701 are an operating system 3701 a, applications3701 b, and modules 3701 c. Examples of an operating system 3701 a,applications 3701 b, modules 3701 c include at least operating systems,applications and modules as discussed herein.

The memory 1450 stores data 3704. Examples of data 3704 include one ormore images 1452, one or more position fixes 1454, orientationinformation 1456 and any other type of data that may be used by an MDCP3700 or that is described herein, or a combination thereof.

The ROM 3702, RAM 3703 and the memory 1450 is for storing informationand instructions for the one or more processors 1460.

The display 1414 may be a liquid crystal device, cathode ray tube,plasma display device or other display device suitable for creatinggraphic images and alphanumeric characters recognizable to a user.

The GUI 3705 includes the graphical user interface 2700 (FIG. 27). TheGUI 3705 may include other types of GUIs that may be used with an MDCP3700.

The input/output device 3706 is for coupling the MDCP 3700 with externalentities. For example, in one embodiment, I/O device 3706 is a modem forenabling wired or wireless communications between an MDCP 3700 and anexternal network such as, but not limited to, the Internet.

Examples of other communications receivers 3707 are satellite radio,terrestrial radio, digital radio, analog radio, Wi-Fi, and Bluetoothprotocol.

An example of a short range communications 3709 is Bluetoothcommunications 1520.

The peripheral computer readable storage media 3760 can be connectedwith the bus 3710. Examples of peripheral computer readable storagemedia 3760 are a disk, DVD, or CD.

External Gnss Raw Observable Provider

According to one embodiment, an external GNSS raw observable providerprovides higher quality reception of GNSS satellite signals than theGNSS chipset that is internal the cellular device 1410 of a mobile datacollection platform 1400, 1500, 3700. For example, in typical GNSSantennae currently used in cellular devices, the GNSS antennae areusually configured for linear polarization and not a circularlypolarized design. This results in a significant loss of signal fromorbiting GNSS satellites, at least 3 dB. However, according to oneembodiment, the external GNSS raw observable provider 3750 utilizes acircularly polarized GNSS antenna, such as a patch antenna, quadrifilierhelix antenna, and planar quadrifiler antenna. The circularly polarizedGNSS antenna of the external GNSS raw observable provider has higherquality reception than linearly polarized antenna of an MDCP. Althoughmany cellular devices' antennas, such as antenna 1412 are linearlypolarized, embodiments are well suited for cellular devices with highquality antennas, such as antennas with a circularly polarized design.

The optional external GNSS raw observable provider 3750 can communicatewith the MDCP 3700 via the short range communications 3709. The externalGNSS raw observable provider 3750 can receive raw observables,communicate the raw observables to the MDCP 3700, and the MDCP 3700 candetermine a position fix based on the raw observables from the externalGNSS raw observable provider 3750. The raw observables from the externalGNSS satellite system are also referred to herein as “external rawobservables” since they are received from a GNSS raw observable provider3750 that is external to the MDCP 3700. The raw observables obtainedfrom the GNSS chipset that is internal to the MDCP 3700 shall bereferred to as “internal raw observables.”

The external raw observables from the external GNSS raw observableprovider 3750 can include raw pseudoranges, and one or more of realcarrier phase information and Doppler Shift Information. The rawpseudoranges, the real carrier phase information and the Doppler ShiftInformation from the external GNSS raw observable provider 3750 shall becalled respectively “external raw pseudoranges,” “external Doppler ShiftInformation,” and “external real carrier phase information.” The MDCP3700 can process the external raw observables, according to variousembodiments described herein, to provide a position fix 1454. The MDCP3700 can use the external raw observables to determine a position fix1454, for example, instead of the internal raw observables from the GNSSchipset 1413 that is part of the MDCP 3700. The external rawpseudoranges can be corrected or smoothed, or a combination thereof, asdescribed herein. A position fix determined based on uncorrectedunsmoothed external raw pseudoranges, corrected unsmoothed external rawpseudoranges, uncorrected smoothed external raw pseudoranges, correctedsmoothed external raw pseudoranges can be smoothed using locallymeasured movement information as described herein. The external rawpseudoranges can be smoothed using either the external Doppler ShiftInformation or the external real carrier phase information according tovarious embodiments described herein. A position fix that is determinedbased on external raw observables can be stored as position fix 1454.

According to one embodiment, the external GNSS raw observable provider3750 has the type of GNSS chipset that is used in cellular devices.Therefore, the GNSS chipset in the GNSS raw observable provider 3750 andthe GNSS chipset 1413 in the mobile data collection platform 1400 mayprovide the same functionality. The GNSS chipset in the GNSS rawobservable provider 3750 may provide more accuracy, as is known in theGNSS receiver art, than the GNSS chipset 1413 in the mobile datacollection platform 1400. An example of an optional external GNSS rawobservable provider 3750, according to one embodiment is a GNSS receiverpositioning system described in U.S. patent application Ser. No.14/134,437, by Large et al., attorney docket number TRMB-3172.CIP10,entitled “GNSS Receiver Positioning System,” filed Dec. 19, 2013.

FIG. 39 depicts an outside view of an external GNSS raw observableprovider 3750, according to one embodiment. The outside view depicts apatch antenna 3901 for wireless communications 3902, for example, withan MDCP 1400, 1500, 3700. The wireless communications 2902 can beBluetooth. For example, the external GNSS raw observable provider 3750and the MDCP 1400, 1500, 3700 can communicate with their respectivewireless communications 3902 and short range communications 3709.

Known Spatial Relationship Between External GNSS Raw Observable Providerand Mobile Data Collection Platform

FIG. 38 depicts an external GNSS raw observable provider 3750 in a knownspatial relationship with a mobile data collection platform 1400,according to one embodiment. The mobile data collection platform 1400can be any mobile data collection platform 1400, 1500, 3700 describedherein. According to one embodiment, the known spatial relationshipbetween the GNSS raw observable provider 3750 and the mobile datacollection platform 1400 is maintained while they are used forcollecting data, such as an image 1452, position fix 1454, andorientation information 1456 as described herein. For example, acoupling mechanism 3850 such as a clip or a joint can be used tophysically couple the mobile data collection platform 1400 and the GNSSraw observable provider 3750 together to provide and maintain a knownspatial relationship between them.

The known spatial relationship can be one or more distances 3820, 3830,3840 (also known as “offsets”) between an antenna 3810 of the GNSS rawobservable provider 3750 and the entrance pupil center 1902 of the MDCP1400 along respective x platform axis 2240, y platform axis 2220, and zplatform axis 2230. More specifically, there may be a first distance3830 between the GNSS raw observable provider 3750 and the entrancepupil center 1902 of the MDCP 1400 along the x platform axis 2240, asecond distance 3820 between the GNSS raw observable provider 3750 andthe entrance pupil center 1902 of the MDCP 1400 along the y platformaxis 2220 and a third distance 3840 between the GNSS raw observableprovider 3750 and the entrance pupil center 1902 of the MDCP 1400 alongthe z platform axis 2230. One or more of these distances 3820, 3830, and3840 can be used as a known spatial relationship between the GNSS rawobservable provider 3750 and the MDCP 1400. Therefore, variousembodiments provide for receiving external raw observables from anexternal GNSS raw observable provider 3750 that is external to themobile data collection platform 1400, wherein an antenna 3810 of theexternal GNSS raw observable provider 3750 and an entrance pupil center1902 of the mobile data collection platform 1400 are in a known spatialrelationship 3820, 3830, and 3840. A position fix 1454 that isdetermined based on external raw observables, one or more of thedistances 3820, 3830, 3840, the tilt angle and the tilt direction can beused to determine the three dimensional position X0, Y0, Z0 of theentrance pupil center 1902 in the local coordinate system according tovarious embodiments described herein.

Mobile Data Collection Platform Examples

Various embodiments provide a mobile data collection platform 1400,1500, 3700 comprising: a cellular device 1410 having: a GNSS chipset1413 that provides raw observables; an antenna 1412 for receiving GNSSpositioning signals and defining a location Xpf, Ypf, Zpf of the mobiledata collection platform 1400, 1500, 3700; and a display 1414; an imagecapturing device 1430 that captures an image 1452, wherein the imagecapturing device 1430 has a known spatial relationship 2406, 2501, 2502with a position determination system reference point, provided forexample by the antenna 1412, of the mobile data collection platform1400, 1500, 3700; an orientation system 1470 that includes a tilt sensor1442 and a compass 1444 and determines orientation information 1456 thatincludes tilt angle 2204 obtained from the tilt sensor 1442 and headinginformation AZ obtained from the compass 1444, wherein the tilt angle2204 is between the mobile data collection platform 1400, 1500, 3700 anda local gravity vector 2270, and the heading information is an azimuthangle AZ between a pointing vector PV of the image capturing device 1430and a reference direction; hardware memory 1450 that stores the image1452, the position fix 1454 and the orientation information 1456; andone or more hardware processors 1460 located outside of the GNSS chipset1413 that accesses the GNSS chipset 1413 and extracts the rawobservables from the GNSS chipset 1413 for use outside of the GNSSchipset 1413 elsewhere in the mobile data collection platform 1400,1500, 3700; captures an image 1452 with the image capturing device 1430,wherein the image 1452 depicts a point of interest; determines aposition fix 1454 of the mobile data collection platform 1400, 1500,3700 based on the raw observables, wherein the position fix 1454provides a location of the mobile data collection platform 1400, 1500,3700 in a GNSS coordinate system; accesses the orientation informationfrom the orientation system 1470, 1440, wherein the orientationinformation 1456 and heading information AZ associated with a threedimensional location, such as the entrance pupil center's location X0,Y0, Z0 or the position fix Xpf, Ypf, Zpf, of the mobile data collectionplatform 1400, 1500, 3700 when the image z52 was captured; and storingthe image 1452, the position fix 1454 and the orientation information1456 and heading information AZ in the hardware memory 1450 of themobile data collection platform 1400, 1500, 3700. Examples of areference direction are true north 2201, magnetic north or a referencetarget at a known location, from which the direction vector can bedetermined, for example, using vector algebra.

According to one embodiment, the raw observables include rawpseudoranges and at least one of real carrier phase information andDoppler Shift Information. For example, according to one embodiment, theraw observables from the GNSS chipset 1413 include raw pseudoranges andat least one of real carrier phase information and Doppler ShiftInformation.

According to one embodiment, the image capturing device is embedded inthe cellular device as an integrated subsystem in a known locationrelative to a GNSS antenna of the cellular device. For example, theimage capturing device 1430 is embedded in the cellular device 1410 asan integrated subsystem in a known location relative to a GNSS antenna1412 of the cellular device 1410. For example, offsets depicted in FIG.27, FIG. 24, and FIG. 25 can be used for determining the known location.

According to one embodiment, the display emulates a pair of crosshairsindicative of an axial direction of an entrance pupil of the imagecapturing device when displaying the image. For example, the display1414 emulates a pair of crosshairs of the crosshair display overlay 2721indicative of an axial direction 2760 of an entrance pupil center 1902of the image capturing device 1430 when displaying the image 1452.

According to one embodiment, the mobile data collection platformincludes a graphical user interface, and wherein the mobile datacollection platform further comprise a bubble level processing logiccoupled with the orientation system that displays a virtualrepresentation of a bubble level on the display. For example, the mobiledata collection platform 1400 includes a graphical user interface 2720,2770. The mobile data collection platform 1400 includes bubble levelprocessing logic 1820 coupled with the orientation system 1470 thatdisplays a virtual representation of a bubble level 2770 on the display1414.

According to one embodiment, a position of a virtual representation of abubble on the display is determined based on the orientation of themobile data collection platform. For example, a position of a virtualrepresentation of a bubble 2770 on the display 1414 is determined basedon the orientation of the mobile data collection platform 1400. Morespecifically, if the mobile data collect platform 1400 is level, thevirtual representation of the bubble 2770 will be in the center 2771 ofthe graphical bubble level overlay 2720. However, if the mobile datacollect platform 1400 is tilting in one or more directions, then thevirtual representation of the bubble 2770 will move in a direction thatcorresponds with the one or more directions that the mobile datacollection platform 1400 is tilting. For example, the graphical userinterface 2720, 2770 emulates a mechanical bubble level.

According to one embodiment, the virtual representation of the bubble isvisible when a tilt angle from the orientation system is less than aselected number in the range from 1 to 10 degrees from a horizontalreference. For example, the virtual representation of the bubble 2770 isvisible when a tilt angle 2204 from the inertial orientation system 1440is less than a specified number in the range from 1 to 10 degrees from ahorizontal reference. An example of a horizontal reference is a plane,such as horizontal plane HP (FIG. 24), or a line, such as second line HL(FIG. 24), that is perpendicular to the local gravity vector.

According to one embodiment, the hardware processor 1460 executesinstructions that provide smoothed pseudoranges by smoothing (1130, FIG.11) raw pseudoranges based on carrier phase information, wherein the rawobservables include the raw pseudoranges, provide corrected smoothedpseudoranges by correcting (1140, FIG. 11) the smoothed pseudorangesbased on external corrections, and determine the position fix Xpf, Ypf,Zpf based on the corrected smoothed pseudoranges.

According to one embodiment, the hardware processor 1460 (FIG. 14)executes instructions that receive tilt angle information, such asinformation about tilt angle 2204 (FIG. 24), from an at least one tiltsensor 1442 (FIG. 14) associated with the inertial orientation system1440 (FIG. 14), receive azimuth angle information, such as informationabout azimuth angle AZ (FIG. 26), from an azimuth sensor, such ascompass 1444 (FIG. 14); and determine a direction of a pointing vectorPV (FIG. 24) emanating from an entrance pupil 1902 (FIG. 24) of theimage capturing device 1430 (FIG. 14). The tilt angle information andthe azimuth angle information can be used to define the orientation ofthe mobile data collection platform 1400 (FIG. 14) relative to a localgravity vector 2270 (FIG. 24).

According to one embodiment, the image 1452 (FIG. 14) depicts an object2799 (FIG. 27), 2930 (FIG. 3) with a known dimension. The object may bea coin, a ruler, or a yardstick, for example, which was placed in thefield of view. The object may be a feature in the field of view that wasnot purposely placed there. For example, the object may be the side of awindow or a door where the length of the side is known and, therefore,be used as scale information.

According to one embodiment, the hardware processor 1460 executesinstructions, for example in response to a user pressing a button of theMDCP 1400, to capture a first image and at a subsequent time, a secondimage with the image capturing device 1430 (FIG. 14) where both thefirst image and the second image depict the point of interest 2250 (FIG.24), determines a first position fix and a second position fix of themobile data collection platform that correlate with respective firstlocation P1 (FIG. 32) and second location P2 (FIG. 32) of the mobiledata collection platform 1400 (FIG. 14) in the GNSS coordinate system,accesses the first and second inertial orientation information from theinertial orientation system 1440, where the first inertial orientationinformation pertains to a first orientation of the mobile datacollection platform 1400 (FIG. 14) for capturing the first image at thefirst location P1 and the second inertial orientation informationpertains to a second orientation of the mobile data collection platform1400 (FIG. 14) for capturing the second image at the second location P2,and stores the second image, the second position fix, and the secondinertial orientation information in the hardware memory 1450 (FIG. 14).The button that the user presses may be a button of the MDCP 1400 forcapturing an image.

According to one embodiment, the hardware processor 1460 executesinstructions that calculates a distance D 3201 (FIG. 32) between thefirst location P1 (FIG. 32) and the second location P2 (FIG. 32) bycalculating a difference between the first position fix for location P1and the second position fix for location P2, wherein the distance D 3201is scale information, and stores the distance D 3201 in the hardwarememory 1450 (FIG. 14).

According to one embodiment, the mobile data collection platformincludes a tilt sensor 1442 (FIG. 14) and a compass 1444 (FIG. 14), thetilt sensor 1442 (FIG. 14) determines a tilt angle 2204 (FIG. 24) andthe compass 1444 (FIG. 14) determines an azimuth angle AZ (FIG. 26).

According to one embodiment, the mobile data collection platform 1400receives external raw observables from an external GNSS raw observableprovider 3750 that is external to the mobile data collection platform1400, wherein an antenna of the external GNSS raw observable provider3750 and an entrance pupil center 1902 of the mobile data collectionplatform 1400 are in a known spatial relationship.

According to one embodiment, the hardware processor further executesinstructions that determine a location of the entrance pupil center 1902based on the known spatial relationship, such as one or more ofdistances 3820, 3830, 3840, between the antenna 3810 and the entrancepupil center 1902.

Computer Readable Storage Medium

Unless otherwise specified, any one or more of the embodiments describedherein can be implemented using non-transitory computer readable storagemedium and computer readable instructions which reside, for example, incomputer-readable storage medium of a computer system or like device.The non-transitory computer readable storage medium can be any kind ofphysical memory that instructions can be stored on. Examples of thenon-transitory computer readable storage medium include but are notlimited to a disk, a compact disk (CD), a digital versatile device(DVD), read only memory (ROM), flash, and so on. As described above,certain processes and operations of various embodiments of the presentinvention are realized, in one embodiment, as a series of computerreadable instructions (e.g., software program) that reside withinnon-transitory computer readable storage memory of a computer system andare executed by the hardware processor of the computer system. Whenexecuted, the instructions cause a computer system to implement thefunctionality of various embodiments of the present invention. Forexample, the instructions can be executed by a central processing unitassociated with the computer system. According to one embodiment, thenon-transitory computer readable storage medium is tangible.

Unless otherwise specified, one or more of the various embodimentsdescribed in the context of FIGS. 1A-39 can be implemented as hardware,such as circuitry, firmware, or computer readable instructions that arestored on non-transitory computer readable storage medium. The computerreadable instructions of the various embodiments described in thecontext of FIGS. 1A-39 can be executed by a hardware processor, such ascentral processing unit, to cause a computer system to implement thefunctionality of various embodiments. For example, according to oneembodiment, various embodiments described herein are implemented withcomputer readable instructions that are stored on computer readablestorage medium that can be tangible or non-transitory or a combinationthereof.

Conclusion

The blocks that represent features in FIGS. 1A-39 can be arrangeddifferently than as illustrated, and can implement additional or fewerfeatures than what are described herein. Further, the featuresrepresented by the blocks in FIGS. 1A-39 can be combined in variousways. The mobile data collection platform 1400, 1500, and 3700 can beimplemented using hardware, hardware and software, hardware andfirmware, or a combination thereof. Further, unless specified otherwise,various embodiments that are described as being a part of the mobiledata collection platform 1400, 1500, 3700, whether depicted as a part ofthe mobile data collection platform 1400, 1500, 3700 or not, can beimplemented using hardware, hardware and software, hardware andfirmware, or a combination thereof.

The above illustration is only provided by way of example and not by wayof limitation. There are other ways of performing the method describedby the flowchart depicted herein.

Although specific operations are disclosed in various flowchartsdepicted herein, such operations are exemplary. That is, embodiments ofthe present invention are well suited to performing various otheroperations or variations of the operations recited in the flowcharts. Itis appreciated that the operations in the flowcharts may be performed inan order different than presented, and that not all of the operations inthe flowcharts may be performed.

The operations depicted in depicted in the flowcharts herein can beimplemented as computer readable instructions, hardware or firmware.According to one embodiment, a mobile data collection platform 1400,1500, and 3700 can perform one or more of the operations depicted inflowcharts herein.

The embodiments described herein transform data or modify data totransform the state of a mobile data collection platform 1400, 1500,3700 for at least the reason that by extracting pseudorange informationfrom a GNSS chipset for use elsewhere, the state of the mobile datacollection platform 1400, 1500, 3700 is transformed from an entity thatis not capable of determining a position fix itself into a mobile datacollection platform 1400, 1500, 3700 that is capable of determining aposition fix itself. In another example, embodiments described hereintransform the state of a mobile data collection platform 1400, 1500, and3700 from not being capable of providing an improved accuracy positionfix to being capable of providing an improved accuracy position fix.

III. Collecting External Accessory Data at a Mobile Data CollectionPlatform that Obtains Raw Observables from an Internal Chipset

Reference will now be made in detail to various embodiments of thesubject matter, examples of which are illustrated in the accompanyingdrawings. While various embodiments are discussed herein, it will beunderstood that they are not intended to limit to these embodiments. Onthe contrary, the presented embodiments are intended to coveralternatives, modifications and equivalents, which may be includedwithin the spirit and scope the various embodiments as defined by theappended claims. Furthermore, in the following Description ofEmbodiments, numerous specific details are set forth in order to providea thorough understanding of embodiments of the present subject matter.However, embodiments may be practiced without these specific details. Inother instances, well known methods, procedures, components, andcircuits have not been described in detail as not to unnecessarilyobscure aspects of the described embodiments.

Unless specifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the description ofembodiments, discussions utilizing terms such as “providing,”“collecting,” “capturing,” “obtaining,” “accessing,” “determining,”“measuring,” “receiving,” “storing,” “illuminating,” “monitoring,”“activating,” “requesting,” “coupling,” “associating,” “maintaining,”“transmitting,” “communicating,” “altering,” “detecting,” “focusing,”“integrating,” “executing,” “performing,” “extracting,” “using,”“correcting,” “smoothing,” “reconstructing,” “modeling,” “improving,”“adjusting,” “filtering,” “discarding,” “removing,” “selecting,”“locating,” “positioning,” “increasing,” “differentiating,” “bridging,”“displaying,” “calculating,” “notifying,” “matching,” “creating,”“generating,” “deactivating,” “initiating,” “terminating,”“interpolating,” “changing,” “replacing,” “causing,” “transformingdata,” “modifying data to transform the state of a computer system,” orthe like, refer to the actions and processes of a computer system, datastorage system, storage system controller, microcontroller, hardwareprocessor, or similar electronic computing device or combination of suchelectronic computing devices. The computer system or similar electroniccomputing device manipulates and transforms data represented as physical(electronic) quantities within the computer system's/device's registersand memories into other data similarly represented as physicalquantities within the computer system's/device's memories or registersor other such information storage, transmission, or display devices.

Overview of Discussion

An external accessory can be used in conjunction with a mobile datacollection platform (MDCP) that provides additional information to themobile data collection platform. Examples of an external accessory arean external GNSS raw observable provider, an external electronicdistance measurement (EDM) accessory, and an external image capturingdevice (ICD) accessory. The external image capturing device accessorymay or may not be an infrared image capturing device (also known as an“external infrared image capturing device accessory”). The externalaccessory can provide the additional data to the mobile data collectionplatform, for example, using a communication method, such as wirelesscommunication or wired communication. The external accessory may be alegacy device.

Another type of external accessory provides an aid to improve thequality of the data collected by the mobile data collection platform.Examples of this second type of external accessory are a monopod, atripod, a physical tape measurer, what is commonly known as a“surveyors' rod,” and an external laser pointer accessory.

Mobile Data Collection Platform

FIG. 40 depicts a block diagram of a mobile data collection platform,according to one embodiment. The mobile data collection platform 4000can include any one or more features of MDCP 1400, 1500.

Examples of a mobile data collection platform 4000 are a cell phone, anon-voice enabled cellular device, a tablet computer, a phablet, and amobile hand-held GNSS receiver. The mobile data collection platform 4000may be used while moving or stationary, since it may be operated in ahand-held position or secured, for example, on a monopod or tripod or amobile platform attached to a vehicle. Examples of a tablet computer arethe Microsoft Surface, Apple iPads, Apple iPad mini, iPad tablet, Nexus7, Samsung Galaxy Tab families, and the Samsung Galaxy Note. Accordingto one embodiment, a mobile data collection platform 4000 is a mobilecommunication device (MCD) with cellular communications capabilities(also referred to as a “cellular communication enabled mobilecommunication device”).

The mobile data collection platform 4000 includes a bus 3710, varioustypes of software 4001, one or more hardware processors 1460, computerusable non-volatile memory (ROM) 3702, computer usable volatile memory(RAM) 3703, hardware memory 1450 that includes data 4004, a display 1414(also referred to as a “display screen” or “screen”), a graphical userinterface (GUI) 3705, input/output device 3706, platform orientationsystem 1470, cellular device 1410, other communications receivers 3707,image capturing device 1430, bubble level system 3820, and short rangecommunication device 3709.

The software 4001 is connected with the ROM 3702, RAM 3703 and thememory 1450. The bus 3710 is connected with the one or more hardwareprocessors 1460, the ROM 3702, the RAM 3703, the memory 1450, thedisplay 1414, the GUI 3705, the input/output device 3706, the platformorientation system 1470, the cellular device 1410, the othercommunications receivers 3707, the image capturing device 1430, thebubble level system 3820 and the short range communication device 4024.The MDCP 4000 can communicate with an optional external GNSS rawobservable provider 3750 and a peripheral computer readable storagemedia 3760.

Examples of software 4001 are an operating system 4001A, applications4001B, and modules 4001C. Examples of an operating system 4001A,applications 4001B, modules 4001C include at least operating systems,applications and modules as discussed herein.

The memory 1450 stores data 4004. Examples of data 4004 include one ormore images 1452, 4152, one or more position fixes 1454, 4154,orientation information 1456, any one or more known spatialrelationships discussed herein, and any other type of data that may beused by an MDCP 4000 or that is described herein, or a combinationthereof.

The GNSS raw observable provider 3750 and external EDM accessory 4020can communicate with the MDCP 3700 via the short range communicationdevice 3709. The external EDM accessory 4020 includes short rangecommunication device 4024 and an EDM system 4022. The MDCP 4000 and theexternal EDM accessory 4020 can communicate with each other with theirrespective short range communication devices 3709 and 4024.

A mounting system 4030 is used to physically couple the external EDMaccessory 4020 and the MDCP 4000 together.

Various other features are depicted in FIG. 40 that have already beendiscussed herein, for example, at least in the context of FIG. 37.

FIG. 41 depicts software 4001 and hardware memory 1450 of a mobile datacollection platform 4000, according to various embodiments.

The software 4001 can include accessory activation logic 4190 andaccessory accessing logic 4170. The accessory activation logic 4190 andthe accessory accessing logic 4170 can reside in either applications4001B or modules 4001C, for example. A mobile data collection platform4000 can be coupled and used with an external accessory, according toone embodiment. The accessory activation logic 4190 detects that animage capture button, such as accept data button 2730, has been pressedand requests information, in response to the button 2730 being pressed,from an external accessory that is attached to the mobile datacollection platform 4000. Alternatively, the accessory activation logic4190 can detect that a timer expired and request information from anexternal accessory in response. The accessory accessing logic 4170receives various types of external accessory data and stores varioustypes of external accessory data. According to various embodiments, thehardware processor 1460 executes the logics 4190 and 4170.

Hardware memory 1450 includes internal image 1452, internal position fix1454, external IR image 4152, external position fix 4154, EDM distancemeasurement 4159, any one or more known spatial relationships 4160discussed herein, and orientation information 1456. The antenna 1412,the display 1414, the logic 4190, 4170, the hardware 1420 are part ofthe mobile data collection platform 4000 and outside of the GNSS chipset1413, which is internal to the mobile data collection platform 4000.Therefore, the GNSS chipset 1413 is also referred to as an “internalGNSS chipset.” An external IR image 4152, the external position fix 4154that is determined based on external raw observables, an EDM distancemeasurement 4159, and optionally one or more known spatial relationships4160 are stored in hardware memory 1450.

The mobile data collection platform 4000 is not required to be leveledas a part of capturing the image 1452, determining the internal positionfix 1454, determining the external position fix 4154, determining theorientation information 1456 or receiving external accessory data, suchas external raw observables that can be used for determining theexternal position fix 4154, external IR image 4152, EDM distancemeasurement 4159, or using an external laser pointer accessory (refer to4412 in FIGS. 44 and 4412 in FIG. 46B) to illuminate a point ofinterest. The orientation information 1456 is associated directly andautomatically with a three dimensional location, such as the positionfix Xpf, Ypf, Zpf (stored as position fix 1454) or the three dimensionallocation X0, Y0, Z0 of an entrance pupil center of the mobile datacollection platform 4000 when an image 1452, 4152 is captured. Themobile data collection platform 4000 is not required to be leveled atthe time that the position fix Xpf, Zpf, Ypf and the orientationinformation 1456 are determined as is common with other opticalmeasurement devices such as theodolites or total stations.

Any one or more of the entities, such as hardware 1420, image capturingdevice 1430, inertial orientation system 1440, compass 1444, hardwarememory 1450, hardware processor 1460, that are part of the mobile datacollection platform 4000 and outside of the cellular device 1410 caninstead be inside of the cellular device 1410. According to oneembodiment, the mobile data collection platform 4000 is a cellulardevice. For example, a tablet type MDCP may contain all the recitedhardware, plus a separate cellphone module, which itself can containsome of the hardware items, including a GNSS chipset. Conversely, thetablet type MDCP may contain a GNSS chipset whose raw observables may bemade available to any of the hard processors associated with the tablet.

Various types of information can be stored, for example, in an EXIF fileassociated with the image 1452, 4152. Examples of information that canbe written into the EXIF file are the GPS position fix 1454, 4154orientation information 1456, the tilt angle, the direction of anazimuth angle (also referred to as an “azimuth direction” or “tiltdirection”), scale information, EDM distance measurement 4159, andantenna-to-entrance-pupil-center-geometric-information, one or moreknown spatial relationships. Any type of information that can be used,for example, for determining one or more of a three dimensional positionof the MDCP's entrance pupil center, a three dimensional position of thecenter of the IR entrance pupil 4630B, a distance from the entrancepupil center to a point of interest and a location of a point ofinterest, as will become more evident, can be stored in the EXIF file.Alternatively, any or more of the same information can be stored asreference information in a suitable reference file associated with theparticular mobile data collection platform.

According to one embodiment, the mobile data collection platform 4000includes a SUPL client, as described herein. The SUPL client can beinside of the cellular device 1410 or can be in the mobile datacollection platform 4000 and outside of the cellular device 1410.According to various embodiments, the mobile data collection platform4000 can include any one or more of features described herein. Forexample, the mobile data collection platform 4000 can include at leastany one or more features or operations depicted in or described in thecontext of FIGS. 1A-39.

FIG. 42 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform 4200 with an entrance pupil 4250 andflash 4210 oriented in a side position 4241, according to oneembodiment. From left to right, the MDCP 4200 is depicted in a portraitscreen view 4201, a portrait back view 4202, a landscape screen view4203, and a landscape back view 4204. The accept data button 2730 (FIG.42, FIG. 43) is oriented on the same side as the display 1414 (FIG. 42,FIG. 43), as discussed herein, as depicted in the screen views. The EDMdistance button 4260 (FIG. 42) is also oriented on the same side as thedisplay 1414. Either the accept data button 2730 or the EDM distancebutton 4260 or both may be a mechanical button or a graphical buttonthat is displayed on the display 1414. However, various embodiments arewell suited for button 4260 and/or button 2730 to be in other positionson either an MDCP or an external accessory.

FIG. 43 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform 4300 with an entrance pupil 4250 andflash 4210 oriented in a center position 4342, according to oneembodiment. From left to right, the MDCP 4300 is depicted in a portraitscreen view 4201, a portrait back view 4202, a landscape screen view4203, and a landscape back view 4204. The accept data button 2730 isoriented on the same side as the display 1414 as depicted in the screenviews. The accept data button 2730 may be a mechanical button or agraphical button that is displayed on the display 1414.

The entrance pupil 4250 and the flash 4210 are exposed on the portraitback view 4202 and landscape back view 4204 in FIG. 42 and FIG. 43. Thepositions of the entrance pupil 4250 and the flash 4210 are marked inthe portrait screen 4201 and landscape screen 4203 views, however theyare not exposed in the portrait screen 4201 and landscape screen 4203views. The accept data button 2730 is exposed and accessible in theportrait screen 4201 and landscape screen 4203 views.

External Accessory Overview

FIG. 44 depicts a block diagram of an external accessory, according toone embodiment.

The external accessory 4400, as depicted in FIG. 44, includes software4401, computer usable non-volatile memory (ROM) 4402, computer usablevolatile memory (RAM) 4403, hardware memory 4450, one or more hardwareprocessors 4460, a bus 4440, a laser transmitter subsystem 4405, areceiver subsystem 4406, a clock 4407, an EDM controller 4408, a signalprocessing and distance data 4409, short range communication device4024, optional wired access 4410, optional infrared (IR) image capturingdevice (ICD) and flash 4411, optional visible laser pointer device 4412,and a rechargeable battery 4430.

The software 4401, one or more hardware processors 4460, ROM 4402, RAM4403, hardware memory 4450, laser transmitter subsystem 4405, receiversubsystem 4406, clock 4407, EDM controller 4408, signal processing anddistance data 4409, short range communication device 4024, wired access4410, optional IR image capturing device and flash 4411, optionalperipheral computer readable storage media 4470, optional visible laserpointer device 4412 and battery 4430, which may be rechargeable ornon-rechargeable, are connected with the bus 4440.

FIG. 44 also depicts a mobile data collection platform 4000 (MDCP) thatcan communicate with the external accessory 4400's short rangecommunication device 4024. The MDCP 4000 and the external accessory 4400can communicate with each other through their respective communicationdevices 3709 and 4024.

The software 4401 includes an operating system 4401A, applications4401B, and modules 4401C. As will become more evident, the time offlight distance calculator 4509A, interface to MDCP logic 4512A, and thedata storage and data transfer logic 4510A (FIG. 45A), the requestedinformation obtaining logic 5920 (FIG. 59), and the requestedinformation providing logic 5930 (FIG. 59) can reside in software, suchas applications 4401B or modules 4401C.

Hardware memory 4450 includes data 4404, for example, that the software4401 uses or stores. The data 4404 may be input to the software 4401, anintermediate result of computations performed by the software 4401 or afinal result of computations performed by the software 4401, or acombination thereof.

The external accessory 4400 can communicate with another entity usingeither wireless communications via short range communication device 4024or wired communications using wired access 4410. The signal processingand distance data 4409 can include, for example, input, intermediateresult, or final result of calculating an estimated distancemeasurement. The external accessory 4400 may include an optionalsupplemental flash. The flash devices that are typically associated witha camera tend to be weak. Therefore, a supplemental flash that has morephotons can be used to provide a more powerful photo flash.

As discussed herein, examples of an external accessory are an externalelectronic distance measurement (EDM) accessory, an external imagecapturing device accessory, an external laser pointer accessory, and anexternal GNSS raw observable provider 3750. As depicted in FIG. 44, theexternal accessory 4400 is a combination accessory that includes anexternal electronic distance measurement (EDM) accessory with features4405, 4406, 4407, 4408, 4409, an external image capturing deviceaccessory with feature 4411, and an external laser pointer accessorywith feature 4412. According to various embodiments, the external imagecapturing device accessory and the external laser pointer accessory areoptional.

External Electronic Distance Measurement Accessory

Electronic distance measurement (EDM) devices are well known in the art.EDM devices can be used to measure distances. An EDM device computes adistance measurement from the EDM device to a point of interest on anobject. For example, the EDM device can transmit light from an EDMtransmitter. The transmitted light can bounce off of an object. Thereflected light can then be received by the EDM receiver. The EDM devicecan determine the distance between the object and the MDCP, for example,based on a difference between the time that the light was transmittedand the time that the reflected light was received (also known as “timeof flight”). According to one embodiment, an electronic distancemeasurement accessory is used to measure a distance between a mobiledistance collection platform and a point of interest, a pseudo point ofinterest, or any point on an object of interest.

The distance measurement, according to one embodiment, provides scaleinformation that can be used for locating the point of interest, and forenabling photogrammetric methods (also known as “photogrammetric dataprocessing”) for determination of other points of interest in the imagecaptured by the image capturing device of the MDCP. The distancemeasured is a scalar quantity but the direction is based on theorientation of the EDM device. When an external EDM accessory isconnected to the MDCP in a known spatial relationship, the orientationof the MCDP provides the vector direction of the distance measurement.Using an EDM minimizes the need for a two-position data capture processnormally needed for photogrammetry when a distance measurement is notpossible. One example of a two-position data capture process is depictedin FIG. 32.

FIG. 45A depicts a block diagram of features of an external EDMaccessory 4020, according to one embodiment.

The external EDM accessory 4020 includes an EDM case 4570A, two lenses4501A and 4502A, a laser transmitter 4503A, a receiver detector 4504A, areceiver processor 4505A, a pulse generator 4506A, a clock 4407, startlogic 4507A, stop logic 4508A, an EDM controller 4408, time of flightdistance calculator 4509A, data storage and data transfer logic 4510A,interface to MDCP logic 4512A, and short range communication device4024. EDM: The EDM case 4570A has a front side 4517A (also referred toas a “front surface”) and a back side 4516A (also referred to as a “backsurface”). The electronic distance measurement accessory 4020's lenses4502A and 4501A are located on the front side 4517A of the accessory4020.

Lens 4501A is associated with the laser transmitter 4503A. Lens 4502A isassociated with the receiver detector 4504A. The laser transmitter 4503Aand the pulse generator 4506A are coupled. The pulse generator 4506A andthe start logic 4507A are coupled. The receiver detector 4504A and thereceiver processor 4505A are coupled and the receiver processor 4505Aand stop logic 4508A are coupled. Start logic 4507A and stop logic 4508Aare both coupled with the clock 4407. Start logic 4507A and EDMcontroller 4408 are coupled. The EDM controller 4408 and the interfaceto MDCP logic 4512A are coupled. The interface to MDCP logic 4512A andthe short range communication device 4024 are coupled. The clock 4407and the time of flight distance calculator 4509A are coupled. The timeof flight distance calculator 4509A and the interface to MDCP logic4512A are coupled. The time of flight distance calculator 4509A and thedata storage and data transfer logic 4510A are coupled. The data storageand data transfer logic 4510A and the short range communication device4024 are coupled.

The EDM case 4570A is depicted as being parallel to the case 4580A ofthe MDCP 4000. The MDCP 4000's case 4580A has a front side 4515A (alsoknown as a “front surface”) and a back side 4518A (also known as a “backsurface”). The MDCP 4000's back side 4518A (also known as a “backsurface”) is the display view side where a user can view the MDCP'sdisplay 1414. The MDCP 4000's lens 4540A is located on the MDCP 4900'sfront side 4515A. The lens 4540A defines the entrance pupil 4250 of theMDCP 4000. The optical axis 4560A is from the entrance pupil 4250. Theoptical axis 4560A is perpendicular to the MDCP's case 4580A. The EDMcase 4570A does not cover the lens 4540A of the MDCP 4000.

The laser transmitter subsystem 4405 (FIG. 44), according to oneembodiment, includes one or more of the receiver detector 4504A, thereceiver processor 4505A, and the stop logic 4508A. The receiversubsystem 4406 (FIG. 44), according to one embodiment, includes one ormore of the laser transmitter 4503A, the pulse generator 4506A, and thestart logic 4507A.

The external EDM accessory 4020 can include a pulse generator 4506A foruse in triggering a laser 4503A to emit a short burst of light 4521A; alaser 4503A designed to emit light 4521A in the infrared spectrum; aclock 4407 that is started by the laser trigger event; an opticalreceiver 4504A that detects a return of the light pulse 4522A from adistant object of interest 4513A and upon detection stops the clock4407; a time of flight distance calculator 4509A for calculating thetime from start to stop, for determining a round trip “time of flight”of the pulse; a communication device 4024, such as Bluetooth, forinteracting with the MDCP 4000; a battery 4430 that is rechargeable ornon-rechargeable; applications software 4401B for managing the entireprocess, including sending of multiple pulses and averaging the results,and formatting estimated distance measurement for use by the MDCP; and aUSB port for software downloading and power supply.

The external EDM accessory 4020 measures the time of flight for a laserpulse to travel to and be reflected from an object of interest 4513Athat a point of interest is on. Upon initiating a measurement epoch, apulse or a series of pulses are transmitted from a laser diode sourceand a clock is started. Upon receipt of the return reflection laserpulse, a detector system is actuated, which then in turn stops theclock. The distance 4599A to the object of interest 4513A is given bymultiplying half the time interval measured by the clock by the speed oflight.

As is well known in the art, the pulse generator 4506A generates a pulsethat is communicated to the laser transmitter 4503A causing the lasertransmitter 4503A to transmit a transmitted signal 4521A that passesthrough the lens 4501A. The start logic 4507A is in communication withthe pulse generator 4506A and uses the clock 4407 to note the time thatthe pulse generator 4506A generated the pulse. The transmitted signal4521A contacts the object of interest 4513A, such as a wall, a door, ora window, that includes a point of interest, as discussed herein. Thetransmitted signal 4521A is reflected by the object of interest 4513Aresulting in a reflected signal 4522A that passes through the lens 4502Aand is detected by the receiver detector 4504A. The transmitted signal4521A and the reflected signal 4522A are separated by a separationdistance 4530A. The external EDM accessory 4020 measures the distance4599A from the external EDM accessory 4020 to the object of interest4513A within a maximum separation distance 4530A. The receiver processor4505A communicates with the stop logic 4508A. The stop logic 4508Aobtains the time from the clock 4407 and notes the time that thereflected signal 4522A was received. According to one embodiment, thetransmitted signal 4521A and the reflected signal 4522A travel along alight beam axis 4585A that is parallel to the optical axis 4560A of theentrance pupil 4250 of the mobile data collection platform 4000.

The time of flight distance calculator 4509A determines the differencebetween the start time and the stop time (also commonly known as “timeof flight”), which can be used to measure the distance 4599A (also knownas “EDM distance measurement”) between the external EDM accessory 4020and the object of interest 4513A. The data storage and data transferlogic 4510A can store various data associated with the processing of thetime of flight distance calculator 4509A, such as the time of flight orthe distance 4599A, or a combination thereof, into memory. The EDMcontroller 4408 can communicate with the interface to MDCP logic 4512Ato transmit the “time of flight” or the distance 4599A to the MDCP 4000using the short range communication device 4024 of the external EDMaccessory 4020. In another embodiment, the external EDM accessory 4020can communicate with the MDCP 4000 using wired communications instead ofshort range communication device 4024.

EDM devices are well known in the art. For more information regardingEDM devices, refer to “DS00 Laser range finder” product manual revision0 by Lightware optoelectronics (Pty) LTD dated 2012, which isincorporated herein by reference.

FIG. 45B depicts, a compact external EDM accessory, according to oneembodiment. FIG. 45B depicts a top view of a compact EDM accessory 4500Bthat bends reflected light 4550B (also known as a reflected signal4522A) that the EDM receiver 4560B receives, according to oneembodiment. By reflecting the reflected light 4550B, for example with amirror 4510B, a more compact EDM accessory 4500B can be provided,according to one embodiment. The EDM accessory 4500B depicted in FIG.45B includes an EDM receiver 4560B, a mirror 4510B, a lens 4520B,optical filter 4590B, a light sensor 4530B and EDM logic 4540B.

The EDM receiver 4560B receives the reflected light 4550B. The mirror4510B reflects a subset of the reflected light 4550B and the reflectedsubset is focused through the lens 4520B. The cone 4570B represents theshape of the path of the reflected subset 4580B between the lens 4520Band the light sensor 4530B. The mirror 4510B alters the path of thereflected light 4550B into focused reflected subset 4580B inside of theexternal EDM accessory 4500B, according to one embodiment. The focusedreflected subset 4580B passes through an optical filter 4590B as ittravels to the light sensor 4530B. The light sensor 4530B detects thefocused reflected subset 4580B coming from the lens 4520B and sends asignal to the EDM logic 4540B. The EDM logic 4540B can measures thedistance (also referred to as “EDM distance measurement”) between theexternal EDM accessory 4500B and the object of interest based on thetime that the light was transmitted by the EDM transmitter and the timethat the light sensor 4530B detects the focused reflected subset 4580B.

According to one embodiment, an external EDM accessory 4500B has a formfactor that integrates with a mobile data collection platform byredirecting the light path. For example, the EDM accessory 4500B thatincludes a mirror 4510B that reflects light provides a compact EDM wherethe back side of the EDM accessory 4500B can be adjacent to and orientedalong the front side of the MDCP 4000 as depicted in FIG. 45A, accordingto one embodiment. Therefore, largest faces of both the EDM accessory4500B and the MDCP 4000 are parallel with each other, according to oneembodiment. A mounting system 4030 can also be used as a part ofintegrating the EDM accessory 4500B with the MDCP 4000.

By design, the EDM laser 4521A is not coaxial with the ICD's opticalaxis. As one of ordinary skill in the art understands, the EDM laserbeam is transmitted along the light beam axis 4585A as depicted, forexample, at least in FIG. 45A. By offsetting the EDM laser beam from thelens/pupil, parts, weight can be saved and complexity reduced. The EDMlaser beam, according to one embodiment, is in close proximity of theICD's entrance pupil 4250 on the MDCP. Since different MDCP's have theirinternal ICD's in different positions, a compromise can be made. Thiscan be accomplished by arranging the EDM laser beam to be locatedbetween the two different positions 4241 and 4342 (refer to FIG. 42 andFIG. 43).

FIG. 45C depicts a block diagram of a legacy EDM (also known as anoff-the-shelf EDM or conventional EDM), according to one embodiment.FIG. 45C depicts a legacy EDM 4500C with a principal axis 4501, displaycontrols 4503C, and an EDM transmit receive beams 4585C between thelegacy EDM's lens and the object of interest 4513A. Most off-the-shelfEDMs 4500C have a similar form factor to that of a handheld cellphone,and most have a similar display on one face of the EDM body. In normaland typical operation, the user holds an off-the-shelf EDM 4500C so thatthe display controls 4503C (also referred to as a screen) is facingupwards, and the EDM beam 4585C (also known as the “light beam”)emanates from the EDM body, outward away from the user and toward theobject of interest 4513A, as shown in FIG. 45C.

Of course an off-the-shelf EDM may be aimed upwards or downwards or inany direction as well. But the salient feature of the off-the-shelf EDMis that the beam pointing vector 4585C lies in a plane parallel to thedisplay plane of the display controls 4503C. However, in the case wherethe EDM accessory 4020 is integrated with an MDCP 4000, an EDM beampointing vector, such as light beam axis 4585A, now lies in a planeperpendicular to the display 1414, as shown in the second FIG. 45A.

In an embodiment, a legacy EDM 4500C can be mounted to the MDCP 4000 sothat the case of the conventional EDM is perpendicular to the MDCP case4580A, as shown in FIG. 45D and FIG. 45E. FIGS. 45D and 45E displayrespective legacy EDMs 4500C that are mounted perpendicularly with anMDCP 4000 so that the legacy EDM 4500C's principal axis 4502D and theMDCP's principal axis 4501C are perpendicular to each other, accordingto various embodiments.

In FIG. 45D a clip 4505D is used to couple the legacy EDM 4500C to theMDCP 4000's side that is closest to the MDCP 4000's lens 4540A formingan L shape where the MDCP 4000 represents the longer leg of the L andthe legacy EDM 4500C represents the shorter leg of the L shape. A userstanding inside the 90 degree angle formed by the two legs of the Lshape can see both the MDCP's display 1414 and the legacy EDM's displaycontrols 4503C while at the same time viewing an object of interest thatthe MDCP's optical axis 4560A is directed toward.

In FIG. 45E, a top/bottom bracket 4505E is used to couple the legacy EDM4500C to approximately the center location of the MDCP 4000 forming a Tshape. A user facing the top of the T shape can see the MDCP's display1414. A user facing one side of the perpendicular line of the T shapecan see the legacy EDM 4500C's display controls 4503C.

In FIGS. 45D and 45E, the EDM transmit receive beams 4585C are alignedand parallel with the EDM's principal axis 4502D. The EDM's principalaxis 4501C, EDM transmit receive beams 4585C are parallel with theMDCP's optical axis 4560A.

FIG. 45F depicts an MDCP 4000 coupled with a legacy EDM 4500C using aseparate box 4550F that includes a mirror 4510F to that reflectsreceived light, such as reflected light 4522A, according to oneembodiment. According to one embodiment, the mirror reflects thereceived light at a 90 degree angle.

FIG. 45G depicts an MDCP 4000 coupled with a legacy EDM 4500G using abend joined box 4550G that includes a mirror 4510G to reflects receivedlight, for example, at a 90 degree angle, according to one embodiment.

FIG. 45H depicts an MDCP 4000 coupled with an integrated external EDMaccessory 4500H that includes a mirror 4510H that reflects the receivedlight at a 90 degree angle, according to one embodiment. The externalEDM accessory 4500H is integrated, for example, because there mirror4510H is a part of the external EDM accessory 4500H, according to oneembodiment. With an integrated external EDM accessory 4500H, the MDCP'sdisplay 1414 can be used to display information for the EDM 4500H.

In an embodiment, a suitable frame, case or mounting system can holdboth the MDCP and the legacy EDM in the right-angle orientation neededto meet the parallel beam requirement, as can be seen in FIGS. 45F-45H.

The display controls 4503C, 4503G, 4503H of the respective EDM 4500C,4500G, 4500H depicted in FIGS. 45F-45H are on the same side of the EDM4500C, 4500G, 4500H as the EDM's lenses 4501A and 4502A. The EDM'sdisplay controls 4503C, 4503G, 4503H and the MDCP's display 1414 are onthe opposite sides of the EDM MDCP combination as depicted in FIGS.45F-45H, according to one embodiment.

Referring to FIGS. 45A, 45B, 45F-45H the MDCP 4000's principal axis4502D and the EDM 4500C, 4500G, 4500H's principal axis 4501C, 4501G,4501H are parallel with each other. As will become evident, the MDCPprincipal axis and the external EDM accessories' principal axis are alsoparallel with each other as depicted at least in FIGS. 47-53, FIG. 55,and FIG. 56. Therefore, in various embodiments, the EDM beam along alight beam axis 4585A, 4585C (FIG. 45A, 45B, 45F, 45G, 45H), can beconfigured to emanate perpendicular to the EDM case 4570A, thus allowinga closer integration of EDM case 4570A and MDCP case 4580A, as shown inFIG. 45A, 45B, 45F, 45G, 45H, FIGS. 47-53, FIG. 55, and FIG. 56.

In contrast, in a conventional handheld EDM, the receiver components arelonger than the thickness of most cellphones or tablet computers, makingit less desirable to locate the EDM detector so that its components arecoaxial and parallel to the optical axis of the camera lens as depictedin FIGS. 45D and 45E. In an embodiment, the reflected beam may bereflected through a 90 degree angle and directed along the case of theEDM, as shown in FIGS. 45A, 45B, 45F, 45G, 45H. A mirror 4510B may beused to perform the right angle reflection. Referring to FIG. 45A, 45B,45F, 45G, 45H the laser transmitter beam 4521A can be provided by asmall laser diode, and may be easily fitted so its beam along light beamaxis 4585A, 4560A is also parallel to the optical axis 4560A from thelens 4540A of the image capturing device 1430.

FIGS. 46A, 46B, and 46C depict views of the outsides of various externalaccessories, according to various embodiments.

FIG. 46A depicts a view of the outside of an external EDM accessory4020, according to one embodiment. The external EDM accessory 4020includes an EDM transmitter 4650A and an EDM receiver 4640A. The EDMtransmitter 4650A and the EDM receiver 4640A are apertures. Transmittedsignals 4521A can be transmitted out of the external EDM accessory 4020through the EDM transmitter 4650A. Reflected signals 4522A, 4550B can bereceived by the external EDM accessory 4020 through the EDM receiver4640A. The EDM transmitter 4650A is part of the receiver subsystem 4406represented by the dashed box. The EDM receiver 4640A is part of thelaser transmitter subsystem 4405 represented by a dashed box.

FIG. 46B depicts a view of the outside of an external accessory 4400,according to one embodiment. The external accessory 4400 includes anexternal EDM accessory, an external laser pointer accessory, and anexternal image capturing device accessory. For example, lasertransmitter subsystem 4405 and receiver subsystem 4406 with theirrespective associated EDM transmitter 4650A and EDM receiver 4640A arepart of the EDM accessory. The laser pointer device 4412 and laser pupil4660B are associated with the laser pointer accessory. The IR flashdevice 4620B, IR flash 4622B, infrared (IR) image capturing device (ICD)4640B, and entrance pupil 4630B are associated with the external imagecapturing device accessory, which may be an external infrared imagecapturing device accessory or an external non-infrared image capturingdevice accessory.

FIG. 46C depicts a view of the outside of an external accessory 4400 andthe outside of an external GNSS raw observable provider 3750 that arecoupled with each other, according to one embodiment. The external GNSSraw observable provider 3750 is located so that it will not obscure theMDCP's entrance pupil or the MDCP's antenna. For example, as depicted inFIG. 46C, the external GNSS raw observable provider 3750 is locatedmidway on the top of the secondary accessory 4400 so that when thecombination accessory, which includes the external accessory 4400 andthe external GNSS raw observable provider 3750, is coupled with the MDCP4000, the external GNSS raw observable provider 3750 will be on top ofthe MDCP 4000 and between the MDCP's entrance pupil 4250 and the MDCP'santenna 1412, as will be discussed in more detail hereinafter.

Packaging Considerations

According to various embodiments, FIGS. 45A, 45F-45H, 48-53, 56 depict afully integrated data capture system. To facilitate a fully integrateddata capture system using the image capturing device 1430, a locationsystem, such as the internal GNSS chipset 1413 and/or the external GNSSraw observable provider 3750, an orientation system 1470, and anelectronic distance measurement system 4022, the EDM case 4570A of theexternal EDM accessory 4020 is coupled in a known spatial relationshipto the MDCP case 4580A of the MDCP. The form factor for the MDCP case4580A is that of a rectangular body with a display 1414 showing bothvisual data and operational controls in a graphical user interface. Thedisplay 1414 also transforms into a visual display of the image capturedby the image capturing device 1430 where the entrance pupil 4250 and thedisplay 1414 are located on opposite sides of the MDCP 4000. This imagecapturing device 1430 may be referred to as the “forward-looking”camera, as shown at least in FIG. 45A. The user typically will hold theMDCP such that the forward looking camera is aimed at a scene containingan object of interest 4513A. The scene may be located in any directionfrom the user: horizontal, vertical-upward or vertical-downward, or anydirection as chosen by the user and the user may or may not be able tosee the display 1414 clearly.

The MDCP 4000 is able, according to various embodiment, tocapture/collect data, as described herein, by pressing accept databutton 2730 (FIG. 42) usually displayed at one end of the display 1414,and often just above the home button at the bottom of the display 1414.Expiration of a timer can be used for capturing or collecting data asdescribed herein. To support timer expiration or single button push datacapture activity, two functions are performed, according to variousembodiments. The single button press or the expiration of a timer thatactuates the image capturing device 1430 to capture an image is alsoused to activate the EDM accessory 4020, calculate the distancemeasurement of the distance 4599A, and return the distance measurementto the MDCP 4000 for compilation with the other data, such as one ormore images, one or more position fixes, and/or orientation information,taken by the MDCP 4000 itself, as discussed herein. The second functionis that of aligning the EDM beam, which travels along light beam axis4585A, with the direction of the optical axis 4560A of the imagecapturing device 1430, which is usually in a center position 4342 of thedisplay 1414 as depicted at least in FIG. 42 and FIG. 43. For example,the optical axis 4560A pointing vector PV is incident on some object ofinterest 4513A, and an image of the object of interest 4513A isdisplayed at the center of the display 1414, often at the center 2750(see FIG. 27) of the crosshair display overlay 2721 (see FIG. 27), ifcrosshair display overlay 2721 is displayed. The MDCP 4000's lens 4540Aand the external EDM accessory 4020's lens 4501A and 4502A are on therespective front sides 4517A, 4515A of the external EDM accessory 4020and the MDCP 4000.

According to one embodiment, an external EDM accessory 4500B integrateswith a mobile data collection platform. FIGS. 45A, 45B, 45D-45H alldepict examples of EDM accessories that can be integrated with a mobiledata collection platform, for example, by providing a light beam axis4585C that is parallel with the optical axis 4560A of the mobile datacollection platform. In another example, the EDM accessory 4500B thatincludes a mirror 4510B that reflects received light provides a compactEDM where the back side of the EDM accessory 4500B can be adjacent toand oriented along the front side of the MDCP 4000 as depicted in FIG.45A, according to one embodiment. Therefore, largest faces of both theEDM accessory 4500B and the MDCP 4000 are parallel with each other,according to one embodiment. In another example of the EDM accessoryintegrating with the mobile data collection platform, the EDM accessorydoes not obscure or cover up the lens 4540A and the entrance pupil 4250of the MDCP. Further, the mounting system 4030 and/or fastener systems4505D, 4505E can also be used as a part of integrating the EDM accessory4500B with the MDCP 4000. A legacy EDM accessory can integrate with anMDCP in an L shape as depicted in FIG. 45D or a T shape as depicted inFIG. 45E. An EDM accessory, according to various embodiments, canintegrate with an MDCP where the principal axes are parallel as depictedin FIGS. 45F-45H. Other examples of the EDM accessory integrating with amobile data collection platform include the known spatial relationshipbetween the EDM accessory and the mobile data collection platform, theuser's ability to clearly see the MDCP's display while operating thecombination of the MDCP and the EDM accessory while viewing a scene, theMDCP controlling the operation of the EDM accessory and the EDMaccessory providing output, such as the EDM distance measurement, inresponse to the MDCP's controls. These are at least a few examples ofthe EDM accessory 4500B integrating with a mobile data collectionplatform, as discussed herein.

By design, the EDM laser 4521A is not coaxial with the ICD's opticalaxis 4560A. The EDM laser beam travels along the light beam axis 4585A.By offsetting the EDM laser beam from the lens/pupil, parts, weight canbe saved and complexity reduced. The EDM laser beam, according to oneembodiment, is in close proximity of the ICD's entrance pupil 4250 onthe MDCP. Since different MDCP's have their internal ICD's in differentpositions, a compromise can be made. This can be accomplished byarranging the EDM laser beam to be located between the two differentpositions 4241 and 4342 (FIG. 42 and FIG. 43).

According to one embodiment, an electronic distance measurement deviceused with an MDCP is fitted to the MDCP in a convenient way for theuser. Off-the-shelf EDMs have a package aspect that is similar to thatof a cellphone: rectangular cross-section with dimensions on the orderof approximately 3 inches wide by 4-6 inches in length, with acomparatively shallow depth, on the order of less than 1 inch, and witha display screen on the large face with user controls. Off-the-shelfEDMs have their laser transmitter and optical return reflection receiverlocated at one narrow end of the package, parallel to the long axis ofthe package, referred to as the top of the device, as depicted in FIG.45C. This is convenient for hand-held operation in which the user aimsthe EDM as if it were a flashlight, towards the object of interest.While such a device could be joined to a cellphone or tablet/phablet,its use would be awkward as it would form a T-shape as depicted in FIG.45E or an L shape as depicted in FIG. 45D. A further considerationderives from the fact that the image capturing device 1430 is on theface opposite the user interface, so the MDCP's user is used to seeingthe image displayed on a large display, such as for example the MDCP'sdisplay 1414, while holding the MDCP so its largest face (front side4515A), that includes the lens 4540A, is directed towards the object ofinterest. Thus a more useful package configuration for joining an EDM toa cellphone type MDCP or tablet type MDCP is to mimic or extend thecurrent shape of the cellphone type MDCP or tablet type MDCP, as if thedepth of the MDCP were being increased, to accommodate the EDMcomponents.

Such an embodiment is shown at least in FIGS. 45A, 45F, 45G, 45H, 48-53in which an EDM package is joined to the front side 4515A of the MDCP.The laser transmitter 4503A and receiver detector 4504A are configuredto emanate from the largest face, such as the front side 4517A, of theEDM package. Thus the EDM transmitter and receiver functions arere-oriented, according to one embodiment, from what is commonlyavailable in off-the-shelf EDMs. According to various embodiments, alaser transmitter is re-packaged, a mirror may be used and improvedoptics may be used to accommodate the laser receiver, as discussedherein.

Specifications for Using an External Electronic Distance MeasurementAccessory with a Mobile Data Collection Platform

The following are a choice of technical parameters that would besuitable for using an external electronic distance measurement accessorywith a mobile data collection platform.

The electronic distance measurement accessory is pulsed by a controlcircuit, such as the EDM controller 4408. The pulse width can be on theorder of 2 to 4 nanoseconds.

According to one embodiment, the wavelength is in the infrared region inthe range of 870 to 930 nm. The pulse power is less than the specifiedlimit for acceptable eye safety.

The working range for the electronic distance measurement accessory isup to 50 meters (m), according to one embodiment. The range may varyaccording to the available reflectivity of the objects of interest. If asuitable laser EDM target is placed in the scene and oriented so that itis perpendicular to the axis 4585A of the laser beam, the 50 m range isachievable.

The diameter of the beam of the exit lens 4501A of the laser isapproximately 5 mm, according to one embodiment and the spot diameter at50 meters is approximately 12 to 15 mm, or less, according to oneembodiment.

The receiver detector 4504A is an avalanche photodiode [APD] orequivalent, according to one embodiment.

An optical bandpass filter is inserted between the receiver detector4504A and the lens 4502A to reduce the effects of noise due to ambientlight. The filter bandwidth is the same as preferred range ofwavelength: 870 to 930 nm, according to one embodiment.

Signal to noise improvements are accomplished by averaging the resultsfrom thousands of pulses. A typical pulse rate is on the order 20,000pulses per second. The external electronic distance measurementaccessory is operated at 300 to 3000 pulses for a measurement epoch.

The accuracy of the distance measurement via the averaging methods is onthe order of 3 mm. The number of measurements that can be made is on theorder 100 per minute, so there is no limitation on the user's ability tocapture data.

Data on each measurement epoch is stored and transmitted to the mobiledata collection platform via the communication device 4024, and isstored and associated with the image captured at the same time in theEXIF file for the image, or in another suitable file with a link to theimage.

The laser transmitter 4503A is offset from the image capturing device1430 by less than 3 centimeters (cm). The axis 4585A of the EDM beam maybe aligned to be parallel with the optical axis 4560A of the imagecapturing device 1430, or may be positioned so that its EDM beam crossesthe optical axis 4560A at some distance, in the range of 10-30 m.

The transmit laser 4503A is positioned on the EDM case 4570A so that itis approximately midway between the available locations on cellphone andtablet type MDCPs. For small cellphone type MDCPs, that is approximately0.75-1 in [2-2.5 cm] from a top side of the electronic distancemeasurement accessory.

The electronic distance measurement accessory can have an infrared flashto aid in data capture when visible light is low, or it is after sunsetand dark. According to one embodiment, it is basically regular visiblelight flash tube with an infrared bandpass filter in front of the outputthat filters out visible light.

The electronic distance measurement accessory is powered by arechargeable battery and an external power converter, well-known n thecellphone arts. The power port may be part of a USB connector, or may bea separate connector.

External Image Capturing Device Accessory

Image capturing devices (ICDs) that are a part of cellular devices (alsoreferred to as “internal image capturing devices”) typically have poorquality lenses where the image is distorted by a variety of lensaberrations, so that what is a uniform distance metric in an image, suchas a checkerboard square pattern, becomes less uniform, particular nearthe edges of the field of view, as depicted in FIG. 21 herein.Therefore, according to one embodiment, an external image capturingdevice accessory that provides higher quality images than the internalimage capturing device can be used in conjunction with a mobile datacollection platform (MDCP). An image that is captured with the externalimage capturing device accessory shall be referred to as an “externalimage” and an image captured with the internal image capturing devicethat is part of the MDCP shall be referred to as an “internal image.”

Many of the examples described herein refer to an external imagecapturing device accessory that is infrared (also referred to as an“external infrared image capturing device accessory”). However, variousembodiments are well suited for an external image capturing deviceaccessory that is not infrared (also referred to as an “externalnon-infrared image capturing device accessory”). An infrared imagecapturing device accessory permits operation in poor visible lightingconditions and at night.

Referring to FIG. 46B, an external IR image capturing accessory includesan IR flash device 4620B and an IR image capturing device 4640B withtheir respective IR flash 4622B and entrance pupil 4630B. The externalimage capturing device is not required to be infrared. According to oneembodiment, the optical axis of the external IR image capturing deviceaccessory and the optical axis of the MDCP 4000's image capturing device1430 are aligned with each other. The external IR image capturing deviceaccessory and the MDCP 4000 can communicate using wired or wirelesscommunications. For example, the external infrared image capturingdevice accessory and the MDCP 4000 can communicate, for example, usingrespective communication devices 4024, 3709. The external infrared imagecapturing device accessory could capture an image that depicts, forexample, a real point of interest or a pseudo point of interest, or bothand communicate the image to the MDCP 4000 using their respectivecommunication devices 4024, 3709. An image captured by an externalcapturing device accessory, whether infrared or non-infrared, can bestored in hardware memory 1450.

According to one embodiment, reflective material may be placed on ornear a point of interest. The reflective material does not need to be onor near a real point of interest but instead located anywhere in thefield of view. If the reflective material is not on a point of interest,the location that the reflective material is on can be treated as apseudo point of interest. The infrared image captured with the externalIR image capturing device accessory will depict the area covered by thereflective material more brightly than if the reflective material werenot on that area.

As discussed herein, the external image capturing device accessory isnot required to be infrared. In the event that the external imagecapturing device is not an infrared device, various features 4620B,4622B, 4640B would not be infrared.

External Laser Pointer Accessory

A laser pointer (also known as a “laser pen”) can emit a narrow beam oflight that illuminates a real point of interest or a pseudo point ofinterest with a bright spot, according to one embodiment.

Referring to FIG. 46B, an external laser pointer accessory can include alaser pointer device 4412 and a laser pupil 4660B, according to oneembodiment.

The laser pointer device 4412 can emit a narrow beam of light throughthe laser pupil 4660B. According to one embodiment, the laser pupil4660B is aligned with the optical axis 4560A of the image capturingdevice that is part of the MDCP 4000. According to one embodiment, thelaser pupil 4660B is within 4 centimeters of the MDCP 4000's entrancepupil 4250. The user of the mobile data collection platform 4000 canilluminate a point of interest with the narrow beam of light, forexample, prior to pressing a button of the MDCP 4000 to capture an imagethat depicts the point of interest. An example of a button that ispressed to capture the image is an accept data button 2730, as discussedherein.

External GNSS Raw Observable Provider

Another example of an external accessory is an external GNSS rawobservable provider. Referring to FIG. 46C, the external GNSS rawobservable provider 3750 is located so that it will not obscure theMDCP's entrance pupil or the MDCP's antenna. For example, as depicted inFIG. 46C, the external GNSS raw observable provider 3750 is locatedmidway on the top of the secondary accessory 4020 so that when thecombination accessory, which includes the external EDM accessory 4020and the external GNSS raw observable provider 3750, is coupled, forexample with a fastener 5210, with the MDCP 4000, the external GNSS rawobservable provider 3750 will be on top of the MDCP 4000 and between theMDCP's entrance pupil 4250 and the MDCP's antenna 1412, as will bediscussed in more detail hereinafter.

The external GNSS raw observable provider 3750 can receive rawobservables, communicate the raw observables to the MDCP 4000, and theMDCP 4000 can determine a position fix based on the raw observables fromthe external GNSS raw observable provider 3750. The raw observables fromthe external GNSS satellite system are also referred to herein as“external raw observables” since they are received from a GNSS rawobservable provider 3750 that is external to the MDCP 4000. The rawobservables obtained from the GNSS chipset that is internal to the MDCP4000 shall be referred to as “internal raw observables.”

The internal raw observables can include internal raw pseudoranges, andone or more of internal real carrier phase information and internalDoppler Shift Information. As discussed herein, the external rawobservables from the external GNSS raw observable provider 3750 caninclude raw pseudoranges, and one or more of real carrier phaseinformation and Doppler Shift Information. The raw pseudoranges, thereal carrier phase information and the Doppler Shift Information fromthe external GNSS raw observable provider 3750 shall be calledrespectively “external raw pseudoranges,” “external Doppler ShiftInformation,” and “external real carrier phase information.” The MDCP4000 can process the external raw observables, according to variousembodiments described herein, to provide a position fix.

The MDCP 4000 can use the external raw observables to determine aposition fix, for example, instead of the internal raw observables in amanner that the internal raw observables are used to determine aposition fix. For example, an uncorrected unsmoothed position fix can bedetermined based on the external raw pseudoranges, a correctedunsmoothed position fix can be determined based on the external rawpseudoranges and external corrections obtained from correction sourcesthat are external to a mobile data collection platform, an uncorrectedsmoothed position fix can be determined based on external rawpseudoranges and external real carrier phase information or externalDoppler Shift Information, or a corrected smoothed position fix can bedetermined based on external raw pseudoranges, external correctionsobtained from correction sources that are external to a mobile datacollection platform, and external real carrier phase information orexternal Doppler Shift Information using various embodiments discussedherein.

Known Spatial Relationships

According to various embodiments, there are known spatial relationshipsbetween various entities discussed herein. For example, there is a knownspatial relationship between the respective entrance pupils of themobile data collection platform (MDCP) and the external IR imagecapturing device (ICD) accessory. In a second example, there is a knownspatial relationship between the entrance pupil of the external IR imagecapturing device accessory and the antenna of the MDCP. In a thirdexample, there is a known spatial relationship between the MDCP'sentrance pupil and the antenna of an external GNSS raw observableprovider. In a fourth example, there is a known spatial relationshipbetween the laser pupil and the MDCP's antenna. In a fifth example,there is a known spatial relationship between the laser pupil and theantenna of an external GNSS raw observable provider.

Therefore, various embodiments are well suited for determining and usingknown spatial relationships and combinations of known spatialrelationships between any two or more entities, such as (1) antenna ofan external GNSS raw observable provider, (2) antenna of an internalGNSS chipset, (3) entrance pupil of an internal image capturing device,(4) entrance pupil of an external IR image capturing accessory, (5)laser pupil of a laser pointer accessory, (6) EDM receiver, and (7) EDMtransmitter. Referring to FIG. 38, distances 3820, 3830, and 3840 areexamples of known spatial relationships.

A known spatial relationship between two entities is a known fixedrelationship, for example, because the known spatial relationship ismaintained, for example, with a physical coupling. A known spatialrelationship is an distance between two entities. A known spatialrelationship is defined as a geometric offset (also referred to as an“offset”) from one entity to another entity, according to oneembodiment. Therefore, according to one embodiment, a mobile datacollection platform is disposed in a known fixed relationship with aknown geometric offset from the external accessory to the mobile datacollection platform, or vice versa. Examples of known spatialrelationships, known fixed relationships, known geometric offsets, knownfixed offsets are 3820, 3830, 3840, 2406, 2501, 2502. However,embodiments are well suited for other known spatial relationshipsbetween other entities as discussed herein.

One or more known spatial relationships can be used for determining athree dimensional position of the center of the IR entrance pupil 4630B,or the entrance pupil 4250 of the image capturing device 1430. The threedimensional position can be determined in the platform coordinate systemor in the local coordinate system defined by the X local axis 2203, Ylocal axis 2201 and Z local axis 2202 (as depicted at least in FIG. 22),for example, in a manner that the three dimensional position of theMDCP's entrance pupil center can be determined as discussed herein.

According to various embodiments, one or more of the known spatialrelationships may be one dimensional, two dimensional or threedimensional.

The one or more known spatial relationships, as described herein, canalso be stored in the hardware memory 1450, as discussed herein, asknown spatial relationships 4160. A user interface can be used forentering known spatial relationships. For example, a user of the MDCPcan measure one or more spatial relationships or the one or more spatialrelationships can be obtained from the MDCP's manufacturerspecification. A list of types of external accessories and a list oftypes of MDCPs can be displayed. One of the types of accessories and oneof the types of MDCPs can be selected. The one or more known spatialrelationships can be determined based on the two selected types. Inanother example, the external accessory can communicate its type to theMDCP and the MDCP can use its type in combination with the externalaccessory's type to determine the one or more spatial relationships.

The relationships are “known,” for example, because they are maintainedin a fixed manner and because they can be obtained, determined and/oraccessed, as discussed herein.

Monpods and Tripods

Various monopods or tripods may be used to support the mobile datacollection platform. A monopod or tripod can be used with the mobiledata collection platform that is alone or with a mobile data collectionplatform that is coupled with an external accessory (also referred toherein as an “MDCP/external accessory combination”). Monopods andtripods are support mechanisms that allow the user to assure minimumcamera movement during image capture. They may allow the user to use animage capturing device 1430 or an image capturing device accessory, at afixed distance above, or in measureable relationship to, ageographically known reference point that may be on the ground of thescene to be measured. Monopods and tripods are commercially availableand well known to photographers and surveying professionals. The supportmechanism can be coupled with a mounting system, for example, by meansof a standard ¼-20 screw mechanism that is built into the externalaccessory. There are numerous suitable monopods and tripods that arecommercially available. By example a monopod such as Benro A35FBR1 maybe used. It has a coupling mechanism that includes a ball head thatenables the user to orient the MDCP to any angle that is appropriate tocapturing the information in the scene. A suitable tripod is the Benromodel BRA2970F.

Coupling Mechanisms

According to various embodiments, a mobile data collection platform andan accessory can be coupled with each other using various types ofcoupling mechanisms. One or more coupling mechanisms can be used tosecurely couple one or more accessories with the MDCP, to maintain theknown spatial relationship between the one or more accessories and theMDCP. Coupling mechanisms can also be used for coupling accessories witheach other.

Examples of coupling mechanisms include hook and loop, strips, adhesive,Velcro, strap, L shaped brackets, U shaped brackets, T shaped brackets,mechanical fasteners, snap fit, receptacles, screws, clothing snaps suchas common found on western style shirts, rotate and lock systems thatcan be cinched tightly, or the like. Examples of mechanical fastenersare mechanical clamps, mechanical brackets or the like.

The coupling mechanism can be a screw mount that is inside of theaccessory's case and is screwed into the back side of the accessory. Thecoupling mechanism can include a bracket that is either attached to thebackside of the accessory, for example, using a screw mount, or thebracket is a part of the accessory's case where the MDCP can slide intothe bracket. The length of the bracket can be adjusted to accommodate avariety of shapes and sizes of MDCP cases. The adjustments may be doneby jo8ining two pieces of the bracket, such as a top piece and a bottompiece, held together by, for example, a screw. The same screw can alsofasten the bracket pieces to the back of the accessory.

FIGS. 47-57 and FIG. 46C depict various types of coupling mechanisms forcoupling a mobile data collection platform with one or more externalaccessories, according to various embodiments.

FIG. 47 depicts a mounting system 4030 for coupling a mobile datacollection platform 4720 with an external accessory 4730, according toone embodiment.

The mounting system 4030 includes an interface adapter 4712 and afastener system 4714. Examples of an MDCP 4720 include a smartphone/mobile digital device (e.g., iPhone®) 4709, among other things asdiscussed herein.

The mounting system 4030 can be used to join the mobile data collectionplatform 4720, such as a smart phone/mobile digital device (e.g.,iPhone®) type mobile data collection platform 4709, with an externalaccessory 4730. According to one embodiment, the fastening system 4714is a standard mounting or fastening system for the external accessory4730 that accepts a variety of types, shapes and sizes of interfaceadapters 4712 for the variety of cellphones, such as smart phone/mobiledigital device (e.g., iPhone®) 4709, that may be used as mobile datacollection platforms 4720, according to various embodiments.

The interface adapter 4712 includes a case 4712B and a knob 4712A,according to one embodiment. The fastener system 4714, according to oneembodiment, is a hole.

The MDCP 4720 and the external accessory 4730 can be snap fitted into orclicked into the case 4712B of the mounting system 4030.

The external accessory 4730 does not covered up (does not obscure) thearea 4790 of the MDCP 4720, which includes the entrance pupil and flash,as indicated by the lines 4780. Further, as can be seen in FIG. 47, whenan external GNSS raw observable positioning system 3750 (FIG. 46C) ismounted on top of another external accessory 4730, the area 4790 is notcovered up. As depicted in FIG. 47, the line 4780 is a straight verticalline. However, various embodiments are well suited for the line 4780 toform an L shape that provides a cut out portion of the accessory so thatnone of the accessory covers up the entrance pupil or flash. Forexample, the lower portion of the accessory's side designed by line 4780could extend below the entrance pupil and the flash while the upperportion of line 4780 remains to the side of the entrance pupil and/orflash forming an L shape to provide the cut out portion. According toone embodiment, the cut out portion is relatively small. For example,the cut out portion is only big enough so that the entrance pupil and/orthe flash are not covered up. According to one embodiment, the mountingsystem 4030 is a mechanical clamp that surrounds an external accessory4730 and an MDCP 4720 without obscuring the area 4790 as discussedherein.

FIG. 48 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform 4820 coupled with an external accessory4400 using a single mounting system 4810 from various views, accordingto one embodiment. Various views are depicted in FIG. 48 to facilitatediscussion of coupling an MDCP with an external accessory 4400. Forexample, at the top of FIG. 48, the external accessory 4400 coupled atlocation 4805 with the mobile data collection platform 4820 is depictedin a top view 4801. To the left and below, the external accessory 4400and the mobile data collection platform 4820 are depicted from theaccessory/MDCP side view 4802. To the right, the external accessory 4400and the mobile data collection platform 4820 are depicted from thedisplay side view 4804. In the middle, the MDCP 4820 and the externalaccessory 4400 are depicted in a side view 4803.

The mobile data collection platform 4820 has a case 4811 that aninterface adapter 4811A is a part of or coupled to. FIG. 48 depicts afastening system 4812 that that includes a case 4812B (also called a“sleeve”) and a fastener 4812A. The external accessory 4400 can be slideinto the case 4812B as depicted by the arrow. The mounting system 4810includes the interface adapter 4811A, the case 4812B and the fastener4812A. Location 4805 is the position where the interface adapter 4811Aand the fastener 4812A couple.

FIG. 48 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform 4820 with an entrance pupil and a flashthat could be at either a side position 4241 or a center position 4342.

FIG. 49 depicts a tablet type mobile data collection platform 4930coupled with an external accessory 4400 using a single interface adapter4951A and fastener 4952A pair type of mounting system 4950 from variousviews, according to one embodiment. Various views are depicted in FIG.49 to facilitate discussion of coupling an MDCP 4930 with an externalaccessory 4400. At the top of FIG. 49, the top view 4991 depicts theexternal accessory 4400 coupled with the mobile data collection platform4930 using a mounting system 4950. To the left and below, theaccessory/MDCP side view 4992 depicts the external accessory 4400coupled with the mobile data collection platform 4930. To the right andbelow, the external accessory 4400 and the mobile data collectionplatform 4930 are depicted from the display view 4994. In the middle andbelow, the MDCP 4930 and the external accessory 4400 are depicted in aleft side view 4993.

In the accessory/MDCP side view 4992, the tablet type MDCP 4930 depictsthe entrance pupil 4250 and the flash 4210 in the center position 4342.The tablet type MDCP 4930 has a case 4951 with an interface adapter4951A that is part of or coupled to the case 4951. The fastening system4952 includes a bracket 4952B and a fastener 4952A. The mounting system4950 includes the interface adapter 4951A, the bracket 4952B and thefastener 4952A.

FIG. 50 depicts a mounting system 5010 that includes three pairs ofinterface adapters 4811A and fasteners 4812A from various views,according to one embodiment. FIG. 50 depicts the mounting system 5010from an accessory/MDCP side view 5002, a side view 5003, and a displayside view 5004, according to one embodiment. FIG. 50 depicts threeinterface adapter/fastener pairs used with both a smart phone/mobiledigital device (e.g., iPhone®) type MDCP 4820 from accessory/MDCP sideview, side view, and display side view. A tablet type MDCP could befastened in the same manner.

More specifically, the smart phone/mobile digital device (e.g., iPhone®)type mobile data collection platform 4820 has a case 5011 that threeinterface adapters 4811A are a part of or coupled to. FIG. 50 depicts afastening system that includes a case 5012B (also called a “sleeve”) andthree fasteners 4812A. The external accessory 4400 can be slide into thecase 5012B as depicted by the arrow. The mounting system 5010 includesthe interface adapters 4811A, the case 5012B and the fasteners 4812A.The three positions 5001 are the locations where the interface adapters4811A and the respective fasteners 4812A couple with each other.

FIG. 51 depicts a mounting system 5150 that includes three interfaceadapters 4951A, three fasteners 4952A and a bracket 5152B, according toone embodiment. FIG. 51 depicts the mounting system 5150 from anaccessory/MDCP side view 5102, a side view 5103, and a display side view5104. The tablet type mobile data collection platform 4930 has a case5051 with three interface adapter 4951A that are part of or coupled tothe case 5051. The fastening system 5152 includes a bracket 5152B andthree fasteners 4952A that are coupled or part of the bracket 5152B. Themounting system 5150 includes the interface adapters 4951A, the bracket5152 and the fasteners 4952A. The three interface adapters 4951A couplewith the respective three fasteners 4952A at the respective positions5101.

FIG. 52 depicts an external combination accessory coupled with twodifferent types of MDCPs from various views, according to variousembodiments. The external combination accessory includes an externalGNSS raw observable provider 3750 coupled with a second externalaccessory 4400, for example, using a snap on mount fastener 5210. Asmart phone/mobile digital device (e.g., iPhone®) type MDCP 4820 can becoupled with the external combination accessory using a snap on mountingsystem 4810, as depicted in the accessory MDCP side view 5291, the sideview 5292 and the top view 5294. A tablet type MDCP 4930 can be coupledwith an external combination accessory using a mounting system 4950, asdepicted in the accessory/MDCP side view 5293 and the top view 5295.

FIG. 53 depicts an external combination accessory coupled with twodifferent types of MDCPs from various views, according to variousembodiments. The external combination accessory includes an externalGNSS raw observable provider 3750 coupled with a second externalaccessory 4400, for example, using a snap on mount fastener 5210. Thesmart phone/mobile digital device (e.g., iPhone®) type MDCP 4820 iscoupled with the external combination accessory using a mounting system5010, as depicted in the accessory MDCP side view 5391, the side view5392 and the top view 5394. The tablet type MDCP 4930 is coupled withthe external combination accessory using a mounting system 5150, asdepicted in the accessory/MDCP side view 5393 and the top view 5395.

As can be seen in FIG. 52 and FIG. 53, the external GNSS raw observableprovider 3750 is positioned approximately in the middle of the top ofthe secondary external accessory 4400 between the MDCP's entrance pupil4250 and the MDCP's antenna 1412 to prevent obscuring the entrance pupil4250 and the antenna 1412. The respective back surfaces of the secondaryexternal accessory 4400 and the external GNSS raw observable provider3750 are flush as indicated respectively at positions 5281, 5282 (FIG.52) of top views 5294, 5295 (FIG. 52) and positions 5381, and 5382 (FIG.53) of top views 5394 and 5395 (FIG. 53). Further, as can be seen in thetop views 5294, 5295 (FIG. 52), 5394 and 5395 (FIG. 53), the backsurfaces of the external combination accessory is adjacent to the MDCPfront surface as indicated respectively at positions 5281, 5282 (FIG.52), 5394, and 5395 (FIG. 53).

Referring to FIGS. 48-53, each of the one or more adapters 4811A, 4951Acouple with one of the respective fasteners 4812A, 4952A. Variousembodiments are well suited for one or more pairs of adapters 4811A,4951A and fasteners 4812A, 4952A.

FIG. 54 depicts a technique for ensuring alignment of coupling of anexternal accessory and MDCP, according to one embodiment. Two mounts5401 and an alignment post 5402 can be used to ensure the alignment,thus, guaranteeing that the external accessory and the MDCP mate in onlyone orientation. Various embodiments are well suited to one or moremounts 5401.

FIG. 55 depicts two different types of mounting systems, according tovarious embodiments. The two types of mounting systems are a snap-onmounting system 5510 and a standard tripod camera mount 5530. Thesnap-on mounting system 5510 includes a male portion 5510A and a femaleportion 5510B where the female portion 5510B snaps on the outside of themale portion 5510A. The female portion 5510B is a part of or coupled toa case 5520 that an MDCP 4000 can be snapped into or slid into asindicated by the arrow. The male portion 5510A is a part of or coupledto the case of an external accessory 4400. 5510A is an example of anadapter 4712 and 5510B is an example of a fastener system 4714. Thestandard tripod camera mount 5530 includes a threaded hole 5530A in thecase 4570A of the external accessory 4400 and a screw 5530B that screwsinto the threaded hole 5530A. The screw 5530B is part of or coupled to apart 5550 that may be a bracket for or a case of an MDCP. In the eventthat the part 5550 is a bracket, an MDCP 4000 can be slide into or besnapped into the part 5550. Various embodiments are well suited to useone or more snap-on mounting system 5510 or one or more standard tripodcamera mounts 5530, or a combination thereof, for coupling an MDCP withan external accessory.

FIG. 56 depicts a smart phone/mobile digital device (e.g., iPhone®) typemobile data collection platform 5600 that is coupled with an externalaccessory 4400 using a mounting system 4030, according to oneembodiment. The MDCP 5600 and the external accessory 4400 are depictedin a front view 5601, a side view 5602 and a top view 5603. The mobiledata collection platform 5600 could have the entrance pupil 4250 andflash 4210 in a side position 4241 or a center position 4342.

FIG. 57 depicts a case 4712B with a fastener option 5740, according toone embodiment. The fastener option 5740 according to one embodiment, ispart of a mounting system 4030 (FIG. 47). As depicted in FIG. 57, thefastener option 5740 includes a fastener system 4714 that is a hole5714A and interface adapter 4712's knob 4712A that can be inserted intothe hole 5714A and twisted 5750 to securely couple the MDCP 4720 andexternal accessory 4730 together.

Referring back to FIG. 46C, a snap-on mount fastener 5210 is used tocouple an external EDM accessory 4020 with an external GNSS rawobservable provider 3750, according to one embodiment.

Legacy External Accessories

According to various embodiments, an external accessory may be a legacydevice. For example, the accessory may be a legacy GNSS raw observableprovider, a legacy IR image capturing device, a legacy image capturingdevice that is not IR, a legacy laser pointing device or a legacyelectronic distance measurement device. The legacy external accessorymay be coupled to the MDCP using Velcro, or some other type of couplingmechanisms that is discussed herein or is well known in the art. FIGS.45D, 45E, 45F, 45G depict examples of legacy EDM devices that are usedas external electronic distance measurement accessories.

Shapes, Sizes, Configurations

An external accessory can have various physical configurations, withdifferent shapes and sizes so long as the external accessory does notcover the entrance pupil of the mobile data collection platform.According to one embodiment, the external accessory 4400 has aconfiguration that allows the flash 4210 and the entrance pupil 4250 ofthe MDCP's internal image capturing device 1430 to be exposed, asdepicted at least in FIG. 42, FIG. 43, 45A, 45D-45H, 47-53, 56. Forexample, although many of the external accessories depicted in thefigures and discussed herein, have a rectangular shape, embodiments canbe practiced using other configurations. For example, the configurationof the external accessory could wrap around a mobile data collectionplatform or allow a mobile data collection platform to slide into theexternal accessory or vice versa. In another example, an “L”configuration that provides a cut out portion, as discussed herein,could be used for external accessories so that none of the entrancepupil 4250 and flash 4210 are covered up.

Collected External Accessory Data and Collected Internal Data

According to various embodiments, various types of information arecollected for determining the distance between a mobile data collectionplatform and a real point of interest or a pseudo point of interest, asdiscussed herein. For example, as discussed herein, the tilt angle, theazimuth angle, a position fix and an image are collected in a mannerthat they are associated with each other. More specifically, the tiltangle, the azimuth angle, the position fix and the image can all becollected during a period that the MDCP is held still. In anotherexample, in response to the user pressing a button on the MDCP, the tiltangle, the azimuth angle, the position fix, and the image are collectedand associated with each other. The raw observables that are extractedfrom the internal GNSS chipset are referred to as “internal rawobservables.” Raw observables that are received by the MDCP from anexternal GNSS raw observable provider are referred to as “external rawobservables.” The image that is obtained with the image capturing devicethat is inside the MDCP is referred to as an “internal image” and animage that is obtained from an external IR image capturing deviceaccessory is referred to as an “external IR image” or “external IRimage.”

The tilt angle, the azimuth angle, the position fix determined based onraw observables that are extracted from an internal GNSS chipset and theinternal image are referred to herein as “collected internal data.”External raw observables, a position fix that is determined based onexternal raw observables, an external image, and an EDM distancemeasurement are referred to as “external accessory data” or “additionaldata.” The external accessory data can be stored in the MDCP's hardwarememory 1450. The external accessory data that is stored in the hardwarememory 1450 is referred to as “collected external accessory data” or“collected additional data.”

According to various embodiments, the additional data from an accessoryis also collected and associated with one or more of the tilt angle, theazimuth angle, the internal position fix determined based on internalraw observables and the internal image. For example, an external imagebe associated with the tilt angle, the azimuth angle and an internal orexternal position fix instead of or in addition to the internal image.In yet another example, external raw observables may be used todetermine the position fix instead of or in addition to determining aposition fix based on internal raw observables.

The techniques for associating tilt angle, the azimuth angle, theposition fix and the internal image can be used for associating theexternal accessory data with the collected internal data. The externalaccessory data can be associated with the collected internal data sothat the internal position fix 1454 and/or the external position fix4154 are the position (also referred to as “particular position”) of theMDCP at the time that one or more of the EDM distance measurement 4159,the tilt angle, the azimuth angle, and the internal image 1452 and/orexternal image 4152 are captured. For example, the MDCP can be heldstill while two or more of the tilt angle, the azimuth angle, internalposition fix, external position fix, internal image, external image, EDMdistance measurement, and highlighting of a real or pseudo point ofinterest using the laser pointer accessory are collected. In anotherexample, one or more of the tilt angle, the azimuth angle, internalposition fix, external position fix, internal image, external image, EDMdistance measurement, and highlighting of a real or pseudo point ofinterest using the laser pointer accessory can be collectedautomatically and instantaneously in response to a timer expiring or auser pressing a button associated with either the MDCP or a buttonassociated respective accessory that the additional data is from. Thebutton that is pressed may be the accept data button 2730. An identifiercan be associated with each of the pieces of external accessory data andcollected internal data for a particular position of the MDCP.

Mobile Data Collection Platform's Processing Logic

FIG. 58 depicts block diagrams of accessory activation logic 4190 andaccessory accessing logic 4170, according to various embodiments. Theaccessory activation logic 4190 includes detect image capture buttonpressed logic 5891 and request information from accessory logic 5892.

The detect image capture button pressed logic 5891 detects that the userof the MDCP 4000 pressed a button, such as the accept data button 2730(also referred to as image capture button 2730) to capture an image. Forexample, the detect image capture button pressed logic 5891 can monitorthat the accept data button 2730 was pressed and communicate, forexample, with wireless communication device 3709 such as Bluetooth, withthe request information from accessory logic 5892 to activate theexternal accessory 4400 and to request external accessory data from theexternal accessory 4400. The button that is pressed may be a mechanicalbutton or a graphical button that is displayed on the display 1414.Alternatively or in addition, the external accessory 4400 can include aflash sensor that detects a flash from the MDCP's flash 4210 (FIG. 42and FIG. 43). Flash sensors are well known in the art of photography.One or more timers can be used instead of the one or more buttonsdiscussed herein. For example, a timer can be used instead of the acceptdata button 2730. Another timer can be used instead of the EDM distancebutton 4260.

The accessory accessing logic 4170 receives external accessory data fromthe external accessory 4400. For example, if the external accessory 4400is an external GNSS raw observable provider 3750 (FIG. 46C), then theexternal raw observables receiving logic 5871 receives external GNSSobservables from the external GNSS raw observable provider. The receivedexternal raw observables can be processed according to variousembodiments described herein to determine a position fix. For example,the external raw observables can include external raw pseudoranges. Theexternal raw observables may also include either Doppler ShiftInformation or real carrier phase information. The external rawpseudoranges can be corrected based on external corrections or smoothed,as discussed herein. The external Doppler shift information or theexternal real carrier phase information can be applied to the externalraw pseudoranges as discussed herein. Therefore, the external rawobservables can be used to provide corrected unsmoothed pseudoranges,uncorrected unsmoothed pseudoranges, corrected smoothed pseudoranges, orcorrected unsmoothed pseudoranges. Then the corrected unsmoothedpseudoranges, uncorrected unsmoothed pseudoranges, corrected smoothedpseudoranges, or corrected unsmoothed pseudoranges can be used todetermine a position fix. The position fix can be smoothed based onlocally measured movement information as discussed herein. The storeexternal accessory data logic 5874 can store the position fix, whichresults from processing the external raw observables, as position fix4154.

If the external accessory 4400 is an external IR image capturing deviceaccessory, then the external IR image receiving logic 5872 receives anexternal IR image from the external IR image capturing device accessory.The store external accessory data logic 5874 can store the external IRimage as the external IR image 4152. If the external accessory 4400 isan external EDM accessory, the external EDM distance receiving logic5873 can receive the EDM distance measurement from the external EDMaccessory. The store external accessory data logic 5874 can store theEDM distance measurement as EDM distance measurement 4159. If theexternal accessory 4400 is an external combination accessory, then theappropriate one or more logics 4170, 5871, 5872, and 5873 can receiveone or more of external raw observables, external IR image, and EDMdistance measurement depending on the capabilities of the externalcombination accessory. The store external accessory data logic 5874 canstore one or more of external IR image 4152, EDM distance measurement4159, and position fix 4154 that is determined based on the external rawobservables, depending which external accessory data the externalcombination accessory provides.

External Accessory's Processing Logic

FIG. 59 depicts processing logic 5900 of an external accessory 4400,according to one embodiment. An external accessory 4400 can include theprocessing logic 5900 in software 4401, such as applications 4401B ormodules 4401C. The processing logic 5900 includes requested informationobtaining logic 5920, requested information providing logic 5930.

The processing logic 5900 is executed in response to principal controlinstructions, as discussed herein, received from a MDCP. For example,the wireless communication device 4024 can receive the request forinformation from MDCP 4000's request information from accessory logic5892 and provide the request for information to the receive request forinformation logic 5910. The request (also known as a “principal controlinstruction”) can be communicated to the requested information obtaininglogic 5920. The requested information obtaining logic 5920 can obtain,depending on the type of external accessory that the external accessory4400 is, one or more of the external raw observables, an external IRimage, and an EDM distance measurement. If the external accessory 4400is a combination accessory, the requested information obtaining logic5920 can coordinate obtaining the various types of external accessorydata that the combination accessory is capable of providing. Forexample, the requested information obtaining logic 5920 canautomatically and instantaneously obtain two or more of external rawobservables, EDM distance measurement, and external IR image dependingon what features are associated with the external combination accessory.The requested information providing logic 5930 can use the wirelesscommunication device 4024 to communicate the one or more of the externalraw observables, an external IR image, and an EDM distance measurementback to the MDCP 4000's wireless communication device 3709.

According to one embodiment, the external accessory 4400 was not builtin a manufacturing facility. For example, the external accessory 4400may be built by a user of the MDCP 4000.

Discussion of Methods

FIG. 60 depicts a flowchart 6000 of a method for collecting externalaccessory data at a mobile data collection platform provided by anexternal accessory of the mobile data collection platform, according toone embodiment.

At 6010, the method begins.

Operations 3520-3550 are performed. The GNSS chipset in operation 3530may be internal to the MDCP or external to the MDCP. For example, rawobservables can be obtained from an internal GNSS chipset 1413 or anexternal GNSS chipset that is part of an external GNSS raw observableprovider 3750. In operation 3540, the position fix can be determinedbased on either internal raw observables or external raw observables orboth, as discussed herein. The position fix defines a location of anantenna, as discussed herein. The raw observables from either theinternal GNSS chipset 1413 or the eternal GNSS raw observable provider3750 can include raw pseudoranges and one of carrier phase informationand Doppler Shift Information.

At 6070, external accessory data is received from an accessory that isexternal to the mobile data collection platform. The external accessorymay be any one or more of an external EDM accessory, an external imagecapturing device accessory, which may be infrared or non-infrared, andan external GNSS raw observable provider accessory. The externalaccessory can be a combination accessory. The external accessory datamay be one or more of external raw observables, an EDM distancemeasurement 4159, and an external image 4152. A position fix 4154 can bedetermined based on the external raw observables as discussed herein.

At 6080, the image 1452, the position fix Xpf, Ypf, Zpf, the orientationinformation 1456 and external accessory data, such as a position fix4154, an external image 4152, and/or an EDM distance measurement 4159,are stored in hardware memory 1450 of the mobile data collectionplatform. The position fix Xpf, Ypf, Zpf is stored as position fix 1454.One or more of the image 1452, the position fix 1454, the orientationinformation 1456, the external image 4152, position fix 4154, and EDMdistance measurement 4159 can be used to determine a location of a pointof interest in the image 1452, 4152 using, for example, photogrammetry.Photogrammetry is well known in the arts. According to one embodiment,the image 1452, the position fix 1454, the orientation information 1456,the external image 4152, position fix 4154, EDM distance measurement4159 can be used to determine a three dimensional location Xpt, Ypt, Zptof the point of interest. According to one embodiment, the threedimensional location Xpt, Ypt, Zpt of the point of interest isdetermined in the local coordinate system.

At 6090, the method ends.

FIG. 61 depicts a flowchart 6100 of a method for collecting externalaccessory data at a mobile data collection platform provided by anexternal accessory of the mobile data collection platform, according toanother embodiment.

At 6110, the method begins.

Operations 3620-3630 are performed. The GNSS chipset may be internal tothe MDCP or external to the MDCP. For example, raw observables that areused to determine the position fix of the cellular device can beobtained from an internal GNSS chipset 1413 or an external GNSS chipsetof an external GNSS raw observable provider 3750. The raw observablesfrom either the internal GNSS chipset 1413 or the eternal GNSS rawobservable provider 3750 can include raw pseudoranges and one of carrierphase information and Doppler Shift Information.

At 6150 external accessory data is received from an accessory that isexternal to the mobile data collection platform. The external accessorymay be any one or more of an external EDM accessory, an external imagecapturing device accessory, and an external GNSS raw observable provideraccessory. The external accessory can be a combination accessory. Theexternal accessory data may be one or more of external raw observables,an EDM distance measurement 4159, and an external image 4152. A positionfix 4154 can be determined based on the external raw observables asdiscussed herein.

The external accessory and the mobile data collection platform arephysically coupled together, according to one embodiment, thus,maintaining a known fixed relationship between the external accessoryand the mobile data collection platform. The known fixed relationshipprovides one or more known geometric offsets between the externalaccessory and the mobile data collection platform. For example, if theexternal accessory is a GNSS raw observables provider, then the one ormore known geometric offsets may be one or more distances 3820, 3830,3840 (FIG. 38). However, embodiments are well suited for other geometricoffsets, for example, for other types of external accessories.

At 6160, the image, the three dimensional position and externalaccessory data are stored in hardware memory. For example, the image1452, the three dimensional position X0, Y0, Z0, and the externalaccessory data can be stored in hardware memory 1450 of the mobile datacollection platform 4000. The external accessory data can include one ormore of the external image 4152, position fix 4154, and EDM distancemeasurement 4159.

The local gravity vector 4170 is local with respect to the cellulardevice 4000, for example, as discussed herein, at the time that the oneor more images 1452, 4152 is captured.

According to one embodiment, the antenna is located at the position fixwhen the image is captured. For example, if the position fix isdetermined based on raw observables obtained from an internal chipset,then the position fix Xpf, Ypf, Zpf defines the location of the antenna1412 (FIG. 14). If the position fix 3860 (FIG. 38) is determined basedon external raw observables accessed from, received from, obtained from,or provided by an external GNSS raw observables provider, then theposition fix defines the location of the antenna 3810 (FIG. 38).

The three dimensional position X0, Y0, Z0 is associated with thecellular device 4000 when one or more images 1452, 4152 is captured. Thethree dimensional position X0, Y0, Z0 is the location of the MDCP'sentrance pupil center at the time that the one or more images 1452, 4152is captured. Instead or in addition, the three dimensional position ofthe cellular device 4000 may be the three dimensional position of theentrance pupil center of the external image capturing device accessoryor some other three dimensional position of the combination of thecellular device and the external accessory when the one or more images1452, 4152 is captured.

The cellular device 4000 is not required to be perpendicular to thelocal gravity vector 2270 at the time of collecting of data, asdescribed herein. For example, the cellular device z00 is not requiredto be perpendicular at the time of the capturing of the one or more theimages 1452, 4152 and the determining of the three dimensional positionX0, Y0, Z0.

At 6170, the method ends.

The detect image capture button pressed logic 5891 detects that the userof the MDCP 4000 pressed a button, such as the accept data button 2730,or a timer expired to capture one or more images 1452, 4152, asdiscussed herein. Alternatively or in addition, the external accessory4400 can include a flash sensor that detects a flash from the MDCP'sflash 4210 (FIG. 42 and FIG. 43). The methods depicted in FIGS. 60 and61 are initiated, according to various embodiments, in response to thedetect image capture button pressed logic 5891 detecting that the userof the MDCP 4000 pressed a button or in response to the flash sensordetecting the flash.

FIG. 62 depicts a flowchart 6200 of a method for collecting externalaccessory data at a mobile data collection platform provided by anexternal accessory of the mobile data collection platform, according toyet another embodiment.

At 6210, the method begins.

At 6212, a determination is made as to what mode the mobile datacollection platform is in. For example, the mobile data collectionplatform can go into an image capture plus EDM mode 6214A in response tothe user selecting a camera icon from the home page displayed on thedisplay 1414 and subsequently pressing the image capture button 2730.Alternatively a timer can be used instead of pressing the image capturebutton 2730. The mobile data collection platform can go into an EDM onlymode 6214B in response to the user pressing the EDM distance button 4260(also referred to as “take a sample distance measurement button”).Alternatively, a timer can be used instead of pressing the EDM distancebutton 4260.

If the mobile data collection platform is in an EDM only mode 6214B,processing proceeds to 6230. If the mobile data collection platform isin an image capture plus EDM mode 6214A, processing proceeds to 6216.According to one embodiment, the EDM accessory operates at peakefficiency, for example, at 300 points per second while in image captureplus EDM mode 6214A and performs in less than peak efficiency when inthe EDM only mode 6214B.

At 6230, the mobile data collection platform instructs the external EDMaccessory to determine an EDM distance measurement. For example, therequest information from accessory logic 5892 can instruct the externalEDM accessory to determine the EDM distance measurement, for example, bytransmitting a principal control instruction via short rangecommunication device 3709 or using wire access 4410, as discussedherein. The external EDM accessory can determine the EDM distancemeasurement as described herein. The measurement that is used as the EDMdistance measurement can be to a point that is displayed nearby, in andaround, the center 2750 of the crosshairs display overlay 2721 (refer toFIG. 27) in the image plane 1950, on the object of interest 4513A. TheEDM distance measurement is determined in response to the EDM accessoryreceiving the control instruction from the MDCP's request informationfrom accessory logic 5892.

At 6232, the mobile data collection platform receives the EDM distancemeasurement. For example, the external EDM accessory can transmit theEDM distance measurement to the mobile data collection platform and theexternal EDM distance receiving logic 5873 can receive the EDM distancemeasurement. The EDM distance measurement is transmitted to the mobiledata collection platform in response to the EDM accessory receiving thecontrol instruction from the MDCP's request information from accessorylogic 5892. The EDM distance measurement can be displayed, for example,on the MDCP's display 1414. Store external accessory data logic 5874 canoptionally store the received EDM distance measurement in the hardwarememory 1450 of the MDCP as EDM distance measurement 4159. Processingproceeds to 6216.

At 6216, an image is captured. 1452 and 4152 are examples of capturedimages. Images can be captured from a single location or from more thanone location, as discussed herein. A distance D 3201 can be determinedbetween two positions P1, P2 that two respective images were capturedthat both depict a point of interest 2250, as depicted in FIG. 32.

At 6218 orientation information of the mobile data collection platformis captured. For example, a tilt angle and tilt direction as provided bythe compass heading can be captured. 3550 is an example of capturingorientation information.

At 6220, the location of the MDCP is captured and the time of that thelocation was captured (also referred to as “time of location capture”)is also captured. The MDCP location may be (1) a position fix asdetermined in 3540, (2) latitude, longitude and altitude, and/or (3) athree dimensional position as determined in 3630. The time may be aGreenwich Mean Time (GMT) or local time.

At 6222, the mobile data collection platform instructs the external EDMaccessory to determine an EDM distance measurement. 6222 is performed ina similar manner to 6230.

At 6224, the EDM distance measurement is received at the mobile datacollection platform. Operation 6224 is performed in a similar manner tooperation 6232.

At 6226, the image, the orientation information, the MDCP location, thetime of capture and the EDM distance measurement are stored. Forexample, store external accessory data logic 5874 can store the imagecaptured at 6216, the orientation information captured at 6218, the MDCPlocation captured at 6220, the time of location capture captured at6220, and the EDM distance measurement received at 6224 into a file. Thefile may be in hardware memory 1450 of the mobile data collectionplatform.

At 6228, the method stops.

FIG. 63 depicts a flowchart 6300 of a method for determining a distance,according to one embodiment.

At 6310, the method begins.

At 6320, a known fixed relationship between an external electronicdistance measurement accessory in a first package and a mobile datacollection platform in a second package is maintained where the firstpackage and the second package are separate packages that are physicallycoupled together. For example, the MDCP's case 4580A and the externalEDM accessory's case 4570A are the respective separate packages. Thefirst package and the second package are physically coupled together.For example, the external electronic distance measurement accessory'scase can include a fastening system 4714 that couples with an interfaceadapter 4712 that maintains a known fixed relationship between therespective cases 4580A and 4570A of the respective mobile datacollection platform and the external electronic distance measurementaccessory. One or more of distances 3820, 3830, and 3840 is an exampleof a known fixed relationship. The one or more distances 3820, 3830, and3840 can be stored in known spatial relationship 4160, as discussedherein.

At 6330, control instructions are received at the external electronicdistance measurement accessory from the mobile data collection platform.The EDM accessory's receive request for information logic 5910 receivesa request for information from the MDCP's request information fromaccessory logic 5892, the requested information obtaining logic 5920obtains the requested information in response to the received requestfor information, and the requested information providing logic 5930provides the requested information to the MDCP's external EDM distancereceiving logic 5873. In another example, the MDCP activates the EDMaccessory, for example, in response to detecting that a button has beenpressed or a timer has expired.

The light beam axis of the external electronic distance measurementaccessory is parallel with an optical axis from an entrance pupil of themobile data collection platform, according to various embodiments. FIGS.45A, 45B, 45D-45H depict examples of the light beam axis 4585A and 4585Cthat is parallel with an optical axis 4560A from an entrance pupil of amobile data collection platform.

The EDM accessory may be activated by the MDCP, according to oneembodiment. For example, a user may push a button or slide a slide barof the EDM accessory to turn the EDM accessory's communication device4024 while putting the EDM accessory in a quiescent mode (also known asa sleep mode) that does not consume much power. The button or slide baronly turns the EDM accessory's communication device 4024. Turning theEDM accessory's communication device 4024 on allows the MDCP to controlthe EDM accessory. The EDM only mode 6214B or the image capture plus EDMmode 6214A can be entered as discussed herein.

In another embodiment, the EDM accessory may activate itself. Forexample, the EDM accessory may be fully activated when the user pushesthe button or slides the slide bar of the EDM accessory.

At 6340, a light beam 4521A is transmitted from a transmit light source4503A, where the transmit light source 4503A is part of the externalelectronic distance measurement accessory 4020 and wherein an axis4585A, 4585C of the light beam 4521A is parallel with an optical axis4560A of an entrance pupil 4250 of the mobile data collection platform4000. The optical axis 4560A is pointing perpendicularly from theentrance pupil 4250, according to one embodiment.

At 6350, a reflected portion 4522A, 4550B, of the light beam 4521A isreceived at a receiving aperture 4560A, 4640A, where the receivingaperture 4560A, 4640A is part of the external electronic distancemeasurement accessory 4020.

At 6360, a measurement of a distance (e.g., “distance measurement) isdetermined based on a time that the light beam 4521A that wastransmitted at 6340 and a time that the reflected portion 4522A, 4550Bof the light beam was received at 6350.

At 6370, the method ends.

According to various embodiments, the methods depicted in FIG. 60, FIG.61, FIG. 62 and FIG. 63 can be performed automatically and almostinstantaneously, for example, in approximately 0.25 second or less. Forexample, approximately 0.25 second or less pass from the time of a datacollection triggering event, such as a button being pressed or a timerexpiring, until all of the external accessory data from one or moreaccessories 4400, 3750 and all of the collected internal data from amobile data collection platform 4000 is stored in the hardware memory1450. Examples of the collected internal data are the tilt angle, theazimuth angle, the position fix determined based on raw observables thatare extracted from an internal GNSS chipset and the internal image fromthe internal ICD and examples of external accessory data are a positionfix that is determined based on external raw observables, an externalimage from an external ICD accessory, and an EDM distance measurement.

Additional Illustrations

An embodiments provides for receiving the principal control instructionsthat include at least one of an instruction that controls an externalelectronic distance measurement accessory, an instruction that controlsan external image capturing device accessory, an instruction thatcontrols an external laser pointer accessory, an instruction thatcontrols an external Global Navigation Satellite Systems (GNSS) rawobservable provider, an instruction requesting that the external GlobalNavigation Satellite Systems (GNSS) raw observable provider transmitexternal raw observables to the mobile data collection platform, and aninstruction requesting that the external electronic distance measurementaccessory transmit data to the mobile data collection platform. Forexample, an external accessory, such as an external electronic distancemeasurement accessory, an external image capturing device accessory, anexternal laser pointer accessory and an external Global NavigationSatellite Systems (GNSS) raw observable provider are not designed to beoperated on their own. Instead, they are designed to be controlled by amobile data collection platform using one or more control instructions,as described herein.

An example of a principal control instruction for any type of accessoryis a control instruction that MDCP's request information from accessorylogic 5892 transmits to the accessory's receive request for informationlogic 5910 or that causes the external accessory to perform somefunction. For an external electronic distance measurement accessory, theprincipal control instruction may be a request for EDM distancemeasurement from the external EDM accessory. For an external imagecapturing device accessory, the principal control instruction may be arequest for an external image from the external image capturing deviceaccessory. For an external laser pointer accessory the principal controlinstruction may be an instruction to transmit a beam of light from theexternal laser pointer accessory. For an external GNSS raw observableprovider, the principal control instruction may be a request forexternal raw observables. Examples of requested data include an EDMdistance measurement 4159 from an external EDM accessory, an externalimage 4152 from an external image capturing device accessory, andexternal raw observables from an external GNSS raw observable providerthat can be used to determine a position fix 4154.

According to one embodiment, turning an external accessory on or off arenot examples of principal control instructions. For example, an externalaccessory can be turned on or off by pressing a button or sliding aslide bar on the external accessory. According to one embodiment, wakingan external accessory up from a sleep mode is an example of a principalcontrol instruction. For example, the external accessory can be turnedon or off by pressing a button on the external accessory. The externalaccessory can go into a sleep mode that saves power while at the sametime enables it to communicate with the mobile data collection platform.Subsequently, the external accessory can be woken up from the sleep modeby receiving a principal control instruction from a mobile datacollection platform that instructs the external accessory to wake up.

An embodiment provides for altering the path of the reflected portion ofthe light beam inside of the external electronic distance measurementaccessory with a mirror 4510B that is part of the electronic distancemeasurement accessory 4400, 4500B. For example, referring to FIGS. 45A,45B, 45F-45H, the path of the reflected portion is bent at a 90 degreeangle, for example, by a mirror. Examples of reflected portion are 4550Band 4522A. Referring to FIGS. 45D and 45E, the path of the reflectedportion is not altered. The reflected portion includes a first reflectedsubset that travels the path prior to the reflecting with the mirror anda second reflected subset that travels the path after the reflectingwith the mirror. Referring to FIG. 45B, an example of a first reflectedsubset is the portion of the reflected light 4550B between an object ofinterest and the mirror 4510B an example of a second reflected subset isthe portion the reflected light 4550B between the mirror 4510B and thelight sensor 4530B.

An embodiment provides for providing a focused second reflected subsetby focusing the second reflected subset with a lens of the externalelectronic distance measurement accessory; and detecting the focusedsecond reflected subset with a light sensor of the external electronicdistance measurement accessory. An example of an external electronicdistance measurement accessory is 4500B. An example of reflected portionis reflected portion 4522A, 4550B (FIGS. 45A, 45B). An example of a lensis 4520B. An example of a light sensor is 4530B. An example of focusedsecond reflected subset is 4580B.

An embodiment provides for receiving, at the external electronicdistance measurement accessory 4020, a request, from the mobile datacollection platform 4000, for a distance measurement, for example, of adistance 4599A between the object of interest 4513A and the externalelectronic distance measurement accessory 4020; and communicating thedistance measurement from the external electronic distance measurementaccessory 4020 to the mobile data collection platform 4000, wherein thedetermining of the distance measurement and the communicating of thedistance measurement are performed in response to the receiving of therequest.

An embodiment provides for the receiving of the request and thecommunicating of the distance measurement of the distance 4599A areperformed by a communication device 4024 that is part of the externalelectronic distance measurement accessory 4020, wherein thecommunication device 4024 is selected from a group consisting of awireless communication device and a wired access communication device4024.

An embodiments is provided for coupling the external electronic distancemeasurement accessory 4020 with the mobile data collection platform 4000where the external electronic distance measurement accessory 4020 has aform factor that integrates with the mobile data collection platform4000 where a light beam axis 4585A of the external electronic distancemeasurement accessory 4020 is parallel with an optical axis 4560A froman entrance pupil 4250 of the mobile data collection platform 4000. Forexample, a form factor can provide a size and shape of the EDM case4570A that integrates with the MDCP case 4580A in a manner describedherein.

Various embodiments provide for an external electronic distancemeasurement accessory 4400, 4020, 4500B for providing data to a mobiledata collection platform 4000, wherein the external electronic distancemeasurement accessory 4400, 4020, 4500B comprises: a front side 4517A ofthe external electronic distance measurement accessory 4400, 4020, 4500Bincludes a transmit light source 4503A and a receiving aperture 4560A,4640A; a back side 4516A of the external electronic distance measurementaccessory 4400, 4020, 4500B is on an opposite side of the front side4517A and the back side 4516A is parallel to the front side 4517A of theexternal electronic distance measurement accessory 4400, 4020, 4500B; afastener system 4714 that couples the back side of the externalelectronic distance measurement accessory 4400, 4020, 4500B to a frontside of the mobile data collection platform 4000, wherein the front sideof the mobile data collection platform includes an entrance pupil 4250and the fastener system maintains a known fixed relationship, such asone or more of distances 3820, 3830, and 3840, between the externalelectronic distance measurement accessory 4400, 4020, 4500B in a firstpackage and the mobile data collection platform 4000 in a secondpackage, where the first and second package are separate packages thatare physically coupled together using the fastener system;receive-request-for-information-logic 5910 that receives a request, fromthe mobile data collection platform 4000, for a distance measurement; atransmit light source 4503A that transmits a light beam, such as 4521A,wherein an axis 4585A of the light beam is parallel with an optical axis4560A of the entrance pupil 4250 of the mobile data collection platform4000; the receiving aperture 4560A, 4640A that receives a reflectedportion, such as 4522A or 4550B, of the light beam; atime-of-flight-distance-calculator 4509A that determines the distancemeasurement of the distance 4599A based on a time that the light beam,such as 4521A, was transmitted by the transmit light source 4503A and atime that the reflected portion, such as 4522A, was received by thereceiving aperture; and requested-information-providing-logic 5930 thatcommunicates the distance measurement to the mobile data collectionplatform 4000.

Various embodiments provide for the external electronic distancemeasurement accessory to further comprises a lens 4520B that focuses thereflected portion; and a light sensor 4530B that detects the focusedreflected portion.

Various embodiments provide for the external electronic distancemeasurement accessory 4400, 4020, 4500B to further comprise acommunication device 4024 that communicates with the mobile datacollection platform 4000, wherein the communication device is selectedfrom a group consisting of a wireless communication device and a wiredaccess communication device.

Various embodiments provide for the electronic distance measurementaccessory 4400, 4020, 4500B to have that integrates with the mobile datacollection platform by providing a light beam axis 4585A that isparallel with the optical axis 4560A. FIGS. 45A, 45B, 45D-45H depict EDMaccessories that have form factors that can be integrated with a mobiledata collection platform by providing a light beam axis 4585A that isparallel with the optical axis 4560A. For example, the EDM accessoriescan be integrated with a mobile data collection platform in an L shape(FIG. 45D), a T shape (FIG. 45E) where the principal axis of the EDMaccessory and the MDCP are perpendicular to each other using mountingsystems that include fastener systems, such as 4505D and 4505E. Inanother example, an EDM accessory can be integrated with a mobile datacollection platform so that the respective principal axis of the EDMaccessory and the mobile data collection platform are parallel with eachother as depicted in FIGS. 45A, 45F-45H, using various mounting systemsas discussed herein. Various embodiments provide for altering the pathof the reflected portion with the mirror 4510B. Various embodimentsprovide for a light beam axis 4585A of the external electronic distancemeasurement accessory 4400, 4020, 4500B is parallel with an optical axis4560A from the entrance pupil 4250 of the mobile data collectionplatform 4000. Various embodiments provide for the back side 4516A ofthe external electronic distance measurement accessory 4400, 4020, 4500Bto be a largest face of the external electronic distance measurementaccessory 4400, 4020, 4500B and the front side 4515A of the mobile datacollection platform 4000 to be a largest face of the mobile datacollection platform 4000. Various embodiments provide for a largestface, such as 4516B, of the external electronic distance measurementaccessory 4400, 4020, 4500B is parallel with a largest face, such as4515A, of the mobile data collection platform 4000. Various embodimentsprovide for a largest face, such as 4516A, of the external electronicdistance measurement accessory 4400, 4020, 4500B to be smaller than alargest face, such as 4515A, of the mobile data collection platform 4000where the entrance pupil 4250 is located on the front side 4515A of themobile data collection platform.

Various embodiments provide for no portion of the external electronicdistance measurement accessory 4400, 4020, 4500B to cover any portion anentrance pupil 4250 of the mobile data collection platform 4000 when theexternal electronic distance measurement accessory 4400, 4020, 4500B iscoupled with the mobile data collection platform 4000. FIG. 47 depictsan area 4790 that includes an entrance pupil and a flash in either acenter position or a side position that are not covered up by anexternal accessory 4730 that is coupled with the MDCP 4720, according tovarious embodiments.

According to one embodiment, the external electronic distancemeasurement accessory has a cut out portion that exposes the entrancepupil of the mobile data collection platform when the externalelectronic distance measurement accessory and the mobile data collectionplatform are coupled with each other. For example, as depicted in FIG.47, the line 4780 is a straight vertical line. However, variousembodiments are well suited for the line 4780 to be L shaped to providea cut out portion of the accessory so that none of the accessory coversup the entrance pupil or flash. For example, the lower portion of theaccessory's side designed by line 4780 could extend below the entrancepupil and the flash in an L shape to provide the cut out portion.

According to one embodiment, the external electronic distancemeasurement accessory includes a mirror 4510B, 4510F, 4510G, 4510H thatalters a path of the reflected portion, such as 4522A, 4550B (FIG. 45A,45B). Various embodiments provide for the reflected portion to include afirst reflected subset and a second reflected subset, the firstreflected subset travels the path prior to the reflected portion beingreflected by the mirror 4510B, 4510F, 4510G, 4510H and the secondreflected subset travels the path after the reflected portion isreflected by the mirror 4510B, 4510F, 4510G, 4510H and the firstreflected subset is at a 90 degree angle with respect to the secondreflected subset. Referring to FIG. 45B, an example of a first reflectedsubset is the portion of the reflected light 4550B between an object ofinterest and the mirror 4510B an example of a second reflected subset isthe portion the reflected light 4550B between the mirror 4510B and thelight sensor 4530B.

Various embodiments provide for the first reflected subset, as discussedherein, being parallel to an optical axis 4560A from the entrance pupil4250 of the mobile data collection platform and the second reflectedsubset, as discussed herein, being parallel with the front side 4517A ofthe external electronic distance measurement accessory 4400, 4020,4500B, the back side 4516A of the external electronic distancemeasurement accessory 4400, 4020, 4500B, and the front side 4515A of themobile data collection platform 4000. Various embodiments provide for alight beam axis 4585A of the external electronic distance measurementaccessory 4400, 4020, 4500B is parallel with an optical axis 4560A fromthe entrance pupil 4250 of the mobile data collection platform 4000.

Various embodiments provide for a principal axis of the mobile datacollection platform 4000 is parallel with a principal axis of theexternal electronic distance measurement accessory 4400, 4020, 4500B,for example, as depicted in FIGS. 45A, 45B, 45F, 45G, and 45H.

Various embodiments provide for an external electronic distancemeasurement accessory 4400, 4020, 4500B for providing data to a mobiledata collection platform 4000, wherein the external electronic distancemeasurement accessory 4400, 4020, 4500B comprises: maintaining meansthat maintains a known fixed relationship, such as one or more distances3820, 3830, and 3840, between the external electronic distancemeasurement accessory 4400, 4020, 4500B and the mobile data collectionplatform 4000, where the electronic distance measurement accessory 4400,4020 and 4500B and the mobile data collection platform 400 are inseparate packages that are physically coupled together, as discussedherein; integrating means that provides a light beam axis 4585A of theexternal electronic distance measurement accessory 4400, 4020, 4500Bthat is parallel with an optical axis 4560A of an entrance pupil 4250 ofthe mobile data collection platform 4000, as depicted in FIGS. 45A, and45D-45H; controlling means, such as 5910 that receives controlinstructions from the mobile data collection platform 4000, where thecontrol instructions control the external electronic distancemeasurement accessory 4400, 4020, 4500B, for example, by causing logics5920 and 5930 to be performed; transmitting means, laser transmitter4503A, that transmits a light beam, such as transmitted light 4521A,from a transmit light source along the light beam axis 4585A; receivingmeans, such as receiver detector 4504A, that receives a reflectedportion, such as 4522A, of the light beam; and determining means, suchas time of flight distance calculator 4509A, that determines a distancemeasurement, for example of a distance 4599A, based on a time that thelight beam was transmitted by the transmitting means and a time that thereflected portion was received by the receiving means.

Various embodiments provide for the external electronic distancemeasurement accessory 4400, 4020, 4500B comprises integrating means thatintegrates the external electronic distance measurement accessory 4400,4020, 4500B with the mobile data collection platform 4000. Examples ofan integrating means include at least one or more of a form factor asdiscussed herein, shapes and sizes of the external electronic distancemeasurement accessory and the mobile data collection platform, fastenersystem 4714, orientations of the external electronic distancemeasurement accessory and the mobile data collection platform when theyare coupled together as depicted, for example, at least in FIGS. 47-53,not covering up area 4790, as discussed herein, when the accessory andthe MDCP are coupled together, and providing a light beam axis 4585A ofthe external electronic distance measurement accessory that is parallelwith an optical axis 4160A of an entrance pupil 4250 of the mobile datacollection platform 4000, at least as depicted in FIGS. 45A, 45D-45H.

Various embodiments provide for the external electronic distancemeasurement accessory 4400, 4020, 4500B further comprising: focusingmeans, such as lens 4520B, that focuses the reflected portion; anddetecting means, such as light sensor 4530B, that detects the focusedreflected portion.

Various embodiments provide for the external electronic distancemeasurement accessory 4400, 4020, 4500B further comprises: receivingmeans, such as receive request for information logic 5910, thatreceives, at the external electronic distance measurement accessory4400, 4020, 4500B, a request, from the mobile data collection platform4000, for the distance measurement, for example of the distance 4599A;and communicating means, such as communication device 4024, thatcommunicates the distance 4599A from the external electronic distancemeasurement accessory 4400, 4020, 4500B to the mobile data collectionplatform 4000.

Various embodiments provide for the receiving means and thecommunicating means being a part of the external electronic distancemeasurement accessory 4400, 4020, 4500B, wherein the receiving means andthe communicating means are selected from a group consisting of awireless communication means and a wired access communication means.Examples of a receiving means is receive request for information logic5910 and communications device 4024 and examples of communicating meansis requested information providing logic 5930 and communications device4024.

According to various embodiments, the external electronic distancemeasurement accessory 4400, 4020, and 4500B further comprises apositioning means that positions the external electronic distancemeasurement accessory with respect to the mobile data collectionplatform in a manner that the light beam axis of the external electronicdistance measurement accessory is parallel with the optical axis from anentrance pupil of the mobile data collection platform. Examples of apositioning means include at least the mirror that bends the reflectedportion, the fastener system 4714, 4505D, 4505E, the orientation of theEDM accessory with respect to the MDCP, which could be an L shape asdepicted in FIG. 45D, a T shape as depicted in FIG. 45E, or parallelprincipal axis as depicted in FIGS. 45F-45H, not covering any portion ofthe MDCP's lens 4540A, the user's ability to clearly and easily see theMDCP's display 1414 as depicted in FIGS. 45A, 45D-45H.

According to one embodiment, the external electronic distancemeasurement accessory 4400, 4020, 4500B further comprises alteringmeans, such as a mirror that alters a path of the reflected portioninside the external electronic distance measurement accessory byreflecting the reflected portion, where the altering means is part ofthe external electronic distance measurement accessory. Examples of analtering means are mirrors 4510B, 4510F, 4510G, 4510H. Examples of areflected portion is reflected portion 4522A, 4550B (FIGS. 45A, 45B).

According to one embodiment, the external electronic distancemeasurement accessory 4400, 4020, 4500B further comprises coupling meansthat couples the external electronic distance measurement accessory withthe mobile data collection platform. An example of a coupling means isfastener system 4714. Other examples of a coupling means are a bracket,a screw, a screw hole, a male portion or female portion of a snap-onmounting system, a hole or a knob that can be inserted into a hole andtwisted.

An embodiment provides for receiving of the external accessory data, asdescribed herein, from the accessory 4400, 4020, 4500B that is externalto the mobile data collection platform 4000, wherein there is a knownspatial relationship, as discussed herein, between the mobile datacollection platform 4000 and the external accessory 4400, 4020, 4500B.

An embodiment provides for receiving the external accessory data from anexternal electronic distance measurement accessory 4400, 4020, 4500B. Anembodiment provides for receiving the external accessory data from anexternal image capturing device accessory that is selected from a groupconsisting of an external infrared (IR) image capturing device and anexternal non-infrared image capturing device. An example of an externalinfrared (IR) image capturing device accessory includes features 4620B,4622B, 4640B 4630B as depicted in FIG. 46B. However, embodiments arewell are also well suited to an external non-infrared image capturingdevice, as discussed herein. An embodiment provides for receiving adistance measurement from an external electronic distance measurementaccessory 4400, 4020, 4500B. An example of a distance measurement is ameasurement of the distance 4599A. An embodiment provides for receivingthe distance measurement that provides a scale factor used inphotogrammetric data processing. For example, the distance measurementcan be used as a scale factor by photogrammetric data processing.

An embodiment provides for illuminating the point of interest with abeam of light from a laser pointer accessory. An example of a laserpointer accessory is an accessory that includes a laser pointer device4412 and laser pupil 4660B.

An embodiment provides for monitoring when a user of the mobile datacollection platform presses a button, such as accept data button 2730,capturing the image 1452 or 4152; activating the external accessory4400, 4020, 4500B in response to detecting that the button was pressed;and requesting the external accessory data from the external accessoryin response to the detecting that the button was pressed.

Various embodiments provide a mobile data collection system forcollecting data, the mobile data collection system comprising: anexternal accessory 4400, 4020, 4500B, for providing external accessorydata to a mobile data collection platform 4000; the mobile datacollection platform 4000 comprising a cellular device 1410, an imagecapturing device 1430, an orientation system 1470, hardware memory 1450,and one or more hardware processors 1460, wherein the cellular devicehas a display 1414 and wherein the image capturing device includes anentrance pupil 3902, 4250; a GNSS raw observable provider 3750 that islocated external to and physically coupled with the mobile datacollection platform, wherein the GNSS raw observable provider 3750includes an antenna 3810, the antenna 3810 and the entrance pupil 3902,4250 are in a known spatial relationship 3820, 3830, and/or 3840 and theantenna 3810 receives GNSS positioning signals that defines a locationof the antenna 3810; the image capturing device 1430 that captures animage 1452, 4152, wherein the image capturing device 1430 is an integralpart of the mobile data collection platform 400 and has a known spatialrelationship with the antenna 3810; the orientation system 1470 includesa tilt sensor and a compass and determines orientation information 1456that includes tilt angle obtained from the tilt sensor and tiltdirection obtained from the compass; the hardware memory 1450 thatstores the image 1452, 4152, the position fix 1454, 4154, externalaccessory data, and the orientation information 1456; wherein the one ormore hardware processors 1460: receives external raw observables from aGNSS raw observable positioning provider 3750 that is outside of themobile data collection platform 4000; captures an image 1452, 4152 withthe image capturing device 1430, wherein the image depicts a point ofinterest; determines the position fix 1454, 4154 of the mobile datacollection platform based on the raw observables, wherein the positionfix defines a location of an antenna in a GNSS coordinate system;accesses the orientation information from the orientation system,wherein the orientation information, which includes the tilt angle andthe tilt direction, is associated with a three dimensional location,such as for example X0, Y0, Z0, of the mobile data collection platformwhen the image was captured; and stores the image, the position fix, theorientation information, and the external accessory data in the hardwarememory of the mobile data collection platform.

According to one embodiment, the antenna 3810 is a circularly polarizedGNSS antenna. According to one embodiment, the raw observables includeraw pseudoranges and one of carrier phase information and Doppler ShiftInformation. According to various embodiments, the mobile datacollection platform is disposed in a known fixed relationship with aknown geometric offset from the external accessory, as discussed herein.

According to various embodiments, the external accessory 4400, 4020,4500B is an external electronic distance measurement accessory, such as4020, 4400, 4500B. According to various embodiments, the externalaccessory is an external image capturing device accessory, such as anaccessory that includes one or more of 4620B, 4622B, 4640B, 4630B (FIG.46B). According to various embodiments, the mobile data collectionplatform 4000 includes an internal GNSS chipset 1413 and the one or morehardware processors 1460 are located outside of the internal GNSSchipset 1413.

According to one embodiment, the mobile data collection platform furthercomprises detect image capture button pressed logic 5891 that monitorswhen a user of the mobile data collection platform presses a button thatinitiates capture of the image; and request information from accessorylogic 5892 that activates the external accessory and requests theexternal accessory data from the external accessory in response todetecting that the button was pressed, wherein the one or more hardwareprocessors executes the detect image capture button pressed logic 5891and the request information from accessory logic 5892.

Various embodiments provide for receiving the external accessory datafrom the external accessory; receiving collected internal data from themobile data collection platform, wherein the position fix of the mobiledata collection platform is the position of the mobile data collectionplatform at a time of the receiving of the external accessory data andthe receiving of the collected internal data; and storing the externalaccessory data with the collected internal data in the hardware memory.For example, the receiving of the external accessory data, the receivingof the collected internal data, and the storing of the externalaccessory data and the collected internal data can be performed in 0.25of a second or less.

In one embodiment, a mounting system 4030 couples the external accessoryand the mobile data collection platform together. According to oneembodiment, the mounting system 4030 is selected from a group consistingof a snap-on mounting system 5510 and a screw mount 5530.

Various embodiments provide for a method of performing data collectionusing a cellular device, the method comprising: capturing an image 1452,4152 that depicts a point of interest using a cellular device 4000;obtaining raw observables from a GNSS raw observable positioningprovider 3750 that is outside of the cellular device, wherein the rawobservables include raw pseudoranges and one of carrier phaseinformation and Doppler Shift Information; determining a position fix1454, 4154 of an antenna 3810 of the GNSS raw observable positioningprovider 3750 based on raw observables from the GNSS raw observablepositioning provider 3750, wherein the GNSS raw observable positioningprovider is outside of the cellular device 4000 and wherein the antenna3810 is in a known spatial relationship with an entrance pupil center3902, 4250 of the cellular device 4000; determining a three dimensionalposition, such as X0, Y0, Z0, of the cellular device based on a localgravity vector and the position fix; receiving external accessory datafrom an accessory 4020, 4400, 4500B that is external to the cellulardevice; and storing the image, the three dimensional position, and theexternal accessory data in hardware memory 1450 of the cellular device,wherein the local gravity vector is local with respect to the cellulardevice, wherein the antenna 3810 is at the position fix when the imageis captured.

Computer Readable Storage Medium

Unless otherwise specified, any one or more of the embodiments describedherein can be implemented using non-transitory computer readable storagemedium and computer readable instructions which reside, for example, incomputer-readable storage medium of a computer system or like device.The non-transitory computer readable storage medium can be any kind ofphysical memory that instructions can be stored on. Examples of thenon-transitory computer readable storage medium include but are notlimited to a disk, a compact disk (CD), a digital versatile device(DVD), read only memory (ROM), flash, and so on. As described above,certain processes and operations of various embodiments of the presentinvention are realized, in one embodiment, as a series of computerreadable instructions (e.g., software program) that reside withinnon-transitory computer readable storage memory of a computer system andare executed by the hardware processor of the computer system. Whenexecuted, the instructions cause a computer system to implement thefunctionality of various embodiments of the present invention. Forexample, the instructions can be executed by a central processing unitassociated with the computer system. According to one embodiment, thenon-transitory computer readable storage medium is tangible.

Unless otherwise specified, one or more of the various embodimentsdescribed in the context of FIGS. 1A-63 can be implemented as hardware,such as circuitry, firmware, or computer readable instructions that arestored on non-transitory computer readable storage medium. The computerreadable instructions of the various embodiments described in thecontext of FIGS. 1A-63 can be executed by a hardware processor, such ascentral processing unit, to cause a computer system to implement thefunctionality of various embodiments. For example, according to oneembodiment, various embodiments described herein are implemented withcomputer readable instructions that are stored on computer readablestorage medium that can be tangible or non-transitory or a combinationthereof.

CONCLUSION

Although many embodiments have been descried with reference to mobiledata collection platform 4000, embodiments are well suited for any ofthe other mobile data collection platforms described herein.

The blocks that represent features in FIGS. 1A-63 can be arrangeddifferently than as illustrated, and can implement additional or fewerfeatures than what are described herein. Further, the featuresrepresented by the blocks in FIGS. 1A-63 can be combined in variousways. A mobile data collection platform can be implemented usinghardware, hardware and software, hardware and firmware, or a combinationthereof. Further, unless specified otherwise, various embodiments thatare described as being a part of the mobile data collection platform,whether depicted as a part of the mobile data collection platform ornot, can be implemented using hardware, hardware and software, hardwareand firmware, or a combination thereof.

The above illustration is only provided by way of example and not by wayof limitation. There are other ways of performing the method describedby the flowchart depicted herein.

Although specific operations are disclosed in various flowchartsdepicted herein, such operations are exemplary. That is, embodiments ofthe present invention are well suited to performing various otheroperations or variations of the operations recited in the flowcharts. Itis appreciated that the operations in the flowcharts may be performed inan order different than presented, and that not all of the operations inthe flowcharts may be performed.

The operations depicted in depicted in the flowcharts herein can beimplemented as computer readable instructions, hardware or firmware.According to one embodiment, a mobile data collection platform canperform one or more of the operations depicted in flowcharts herein.

The embodiments described herein transform data or modify data totransform the state of a mobile data collection platform for at leastthe reason that by extracting pseudorange information from a GNSSchipset for use elsewhere, the state of the mobile data collectionplatform is transformed from an entity that is not capable ofdetermining a position fix itself into a mobile data collection platformthat is capable of determining a position fix itself. In anotherexample, embodiments described herein transform the state of a mobiledata collection platform from not being capable of providing an improvedaccuracy position fix to being capable of providing an improved accuracyposition fix.

Example embodiments of the subject matter are thus described. Althoughthe subject matter has been described in a language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

Various embodiments have been described in various combinations andillustrations. However, any two or more embodiments or features may becombined. Further, any embodiment or feature may be used separately fromany other embodiment or feature. Phrases, such as “an embodiment,” “oneembodiment,” among others, used herein, are not necessarily referring tothe same embodiment. Features, structures, or characteristics of anyembodiment may be combined or separated in any suitable manner with oneor more other features, structures, or characteristics.

What is claimed is:
 1. A method of collecting external accessory data ata mobile data collection platform provided by an external accessory ofthe mobile data collection platform, the method comprising: capturing animage that includes a point of interest, wherein the capturing isperformed by an image capturing device that is an integral part of themobile data collection platform; obtaining external raw observables froma Global Navigation Satellite System (GNSS) raw observables provider,wherein the GNSS raw observables provider is external to and coupledwith the mobile data collection platform; determining a position fixbased on the external raw observables, wherein the position fix definesa location of an antenna; calculating a location of an entrance pupil asan offset from the location of the antenna; determining orientationinformation comprising a tilt angle and an azimuth angle, wherein theposition fix and the orientation information are associated with a threedimensional location of the mobile data collection platform when theimage was captured; receiving accessory data from an accessory that isexternal to and physically coupled with the mobile data collectionplatform in a fixed relationship; and storing the image, the positionfix, the orientation information and the external accessory data inhardware memory of the mobile data collection platform, wherein thecapturing, obtaining, determining of the position fix, determining ofthe orientation information, and the storing are performed by one ormore hardware processors that are part of the mobile data collectionplatform.
 2. The method as recited by claim 1, wherein the receiving ofthe external accessory data from the accessory further comprises:receiving the external accessory data from an external electronicdistance measurement accessory.
 3. The method as recited by claim 1,wherein the receiving of the external accessory data from the accessoryfurther comprises: receiving the external accessory data from anexternal image capturing device accessory that is selected from a groupconsisting of an external infrared (IR) image capturing device and anexternal non-infrared image capturing device.
 4. The method as recitedby claim 1, wherein the receiving of the external accessory data furthercomprises: receiving a distance measurement from an external electronicdistance measurement accessory.
 5. The method as recited by claim 4,wherein the receiving of the distance measurement further comprises:receiving the distance measurement that provides a scale factor used inphotogrammetric data processing.
 6. The method as recited by claim 1,wherein the method further comprises: illuminating the point of interestwith a beam of light from a laser pointer accessory.
 7. The method asrecited by claim 1, wherein the method further comprises: monitoringwhen a user of the mobile data collection platform presses a buttoncapturing the image; activating the external accessory in response todetecting that the button was pressed; and requesting the externalaccessory data from the external accessory in response to the detectingthat the button was pressed.
 8. A mobile data collection system forcollecting data, the mobile data collection system comprising: anexternal accessory that provides external accessory data to a mobiledata collection platform; an external Global Navigation Satellite System(GNSS) raw observables provider includes an antenna, wherein the antennareceives GNSS positioning signals that define a location of the antennaand wherein the external GNSS raw observables provider is external toand physically coupled with a mobile data collection platform; themobile data collection platform includes: a cellular device thatincludes a display for displaying images and an internal GNSS chipset;an image capturing device that captures an image through an entrancepupil of the mobile data collection platform; an orientation system thatincludes a tilt sensor and a compass and determines orientationinformation that includes tilt angle obtained from the tilt sensor andheading information obtained from the compass, wherein the tilt angle isbetween the mobile data collection platform and a local gravity vector,and the heading information is an azimuth angle between a pointingvector of the image capturing device and a reference direction; hardwarememory that stores the image, a position fix and the orientationinformation; and one or more hardware processors that executesinstructions which: receive external raw observables from the externalGNSS raw observables provider; capture the image with the imagecapturing device, wherein the image depicts a point of interest andwherein the image is captured while the antenna is at the location;determine the position fix associated with the mobile data collectionplatform based on the external raw observables, wherein the position fixprovides the location of the antenna in a GNSS coordinate system;calculate a location of the entrance pupil as an offset from thelocation of the antenna; access the orientation information from theorientation system, wherein the orientation information and the headinginformation are associated with a three dimensional location of themobile data collection platform when the image was captured; and storethe image, the position fix, the orientation information, the headinginformation and the external accessory data in the hardware memory ofthe mobile data collection platform, wherein the hardware memory and theone or more hardware processors are outside of the internal GNSSchipset.
 9. The mobile data collection system of claim 8, wherein theantenna is a circularly polarized GNSS antenna.
 10. The mobile datacollection system of claim 8, wherein the raw observables include rawpseudoranges and one of carrier phase information and Doppler ShiftInformation.
 11. The mobile data collection system of claim 8, whereinthe mobile data collection platform is disposed in a known fixedrelationship with a known geometric offset from the external accessory.12. The mobile data collection system of claim 8, wherein the externalaccessory is an external electronic distance measurement accessory. 13.The mobile data collection system of claim 8, wherein the externalaccessory is an external image capturing device accessory.
 14. Themobile data collection system of claim 8, wherein the mobile datacollection platform includes an internal GNSS chipset and the one ormore hardware processors are located outside of the internal GNSSchipset.
 15. The mobile data collection system of claim 8, wherein themobile data collection platform further comprises: detect image capturebutton pressed logic that monitors when a user of the mobile datacollection platform presses a button that initiates capture of theimage; and request information from accessory logic that activates theexternal accessory and requests the external accessory data from theexternal accessory in response to detecting that the button was pressed,wherein the one or more hardware processors executes the detect imagecapture button pressed logic and the request information from accessorylogic.
 16. The mobile data collection system of claim 15, wherein theone or more hardware processors further performs: receiving the externalaccessory data from the external accessory; receiving collected internaldata from the mobile data collection platform, wherein the position fixof the mobile data collection platform is the position of the mobiledata collection platform at a time of the receiving of the externalaccessory data and the receiving of the collected internal data; andstoring the external accessory data with the collected internal data inthe hardware memory.
 17. The mobile data collection system of claim 8,wherein a mounting system couples the external accessory and the mobiledata collection platform together.
 18. The mobile data collection systemof claim 17, wherein the mounting system is selected from a groupconsisting of a snap-on mounting system and a screw mount.
 19. Anon-transitory computer readable storage medium having computer readableinstructions stored thereon for causing a computer system to perform amethod of performing data collection using a cellular device, the methodcomprising: capturing an image that depicts a point of interest using acellular device; obtaining external raw observables from an externalGlobal Navigation Satellite System (GNSS) raw observables provider;determining a position fix based on the external raw observables,wherein the position fix defines a location of an antenna of theexternal GNSS raw observable provider and wherein the antenna isdisposed at a known fixed offset from an entrance pupil center of thecellular device; determining a three dimensional position of thecellular device based on a local gravity vector and the position fix;receiving external accessory data from an accessory that is external tothe cellular device; and storing the image, the three dimensionalposition, and the external accessory data in hardware memory of thecellular device, wherein the local gravity vector is local with respectto the cellular device, wherein the antenna is located at the positionfix when the image is captured.
 20. The non-transitory computer readablestorage medium as recited by claim 19, wherein the receiving of theexternal accessory data from the accessory further comprises: receivingthe external accessory data from an external electronic distancemeasurement accessory.
 21. The non-transitory computer readable storagemedium as recited by claim 19, wherein the receiving of the externalaccessory data from the accessory further comprises: receiving theexternal accessory data from an external image capturing deviceaccessory.
 22. The non-transitory computer readable storage medium asrecited by claim 19, wherein the receiving of the external accessorydata further comprises: receiving an external image from an externalimage capturing device accessory.
 23. The non-transitory computerreadable storage medium as recited by claim 19, wherein the receiving ofthe external accessory data from the accessory further comprises:receiving the external accessory data from a combination accessory thatincludes an external electronic distance measurement accessory, and atleast one of an external infrared image capturing device accessory, andan external GNSS raw observable provider accessory.
 24. Thenon-transitory computer readable storage medium as recited by claim 19,wherein the method further comprises: detecting when a user of thecellular device presses a button to capture the image; activating theexternal accessory in response to the detecting that the button waspressed; and requesting the external accessory data from the externalaccessory in response to the detecting that the button was pressed. 25.The non-transitory computer readable storage medium of claim 24, whereinthe method further comprises: receiving the external accessory data fromthe external accessory; receiving collected internal data from thecellular device, wherein the position fix of the cellular device is theposition of the cellular device at a time of the receiving of theexternal accessory data and the receiving of the collected internaldata; and associating the external accessory data with the collectedinternal data.